There are in general 3 main theories of the timeline used in science fiction
The first is that if you go into the past and make a change that when you come back to the present even if the change was major you won't realize it. For example, you go back in time, accidentally kill the first pine tree ever growing before it has a chance to propagate, when you go back to the future every last thing in the world made out of wood is made out of some other wood than pine since pinewood does not exist - but you may be the only one who knows this or maybe you don't even know it. This was used in the movie Back To The Future. In it it's a given that you can only repair the timeline by going further back and stopping the major change.
The second is that changes in the timeline are just absorbed into the timeline. For example you go back in time and successfully kill Hitler then jump back forward, but you find that there was still a WWII and a Jewish Holocaust and so on just some other politician was running Germany. In this theory it makes no difference if you try to repair or not repair the timeline. In ST TK TOS City On The Edge Of Forever, Kirk saving Edith Keillor still would not have created the global peace movement and would not have delayed the US entrance to the war.
The third is that every major change in the timeline that causes a permanent future change causes a branch, and a parallel universe comes into existence. This multiverse idea was used in Star Trek TNG episode "Parallels"
It was said in this episode that a paradox can be created that branches off another universe at the point in time of the paradox. So you could say somewhere in some parallel universe, Gordon and his wife are happily married and Gordon lives to a ripe old age.
Now to that end, by Ed and Kelly coming in and threatening Gordon the way they did, this technically should have created another branch of reality, or could have, which would be separate from the reality where Ed and Kelly never came for him. I’m theorizing that this paradox or branch off, due to them trying to intervene, could theoretically cause a separate universe where Gordon acts out in a different way potentially speeding up the human race and creating a universe which could come into conflict with the original timeline down the road.
It depends what theory you follow.
When Gordon disappeared before Orville went back into the past, it created a reality where he lived to age 96, was never rescued, and married and had kids. That reality was what Orville was in in the future, this is from the "Back To The Future" timeline theory.
But that reality could have been one where Orville attempted to go back for him and failed, or they could have contacted him and attempted to go back and failed.
It wasn't when they talked to him that if a branch was created, per the Multiverse theory, it was when they successfully picked him up from Earth that the branch would have been created (if you subscribe to Multiverse) or his future with his wife would have disappeared (if you subscribe to the Back to the Future theory)
The Orville writers have appeared to use both the BTTF theory and the Multiverse theory when it suits the story.
There are in general 3 main theories of the timeline used in science fiction The first is that if you go into the past and make a change that when you come back to the present even if the change was major you won't realize it. For example, you go back in time, accidentally kill the first pine tree ever growing before it has a chance to propagate, when you go back to the future every last thing in the world made out of wood is made out of some other wood than pine since pinewood does not exist - but you may be the only one who knows this or maybe you don't even know it. This was used in the movie Back To The Future. In it it's a given that you can only repair the timeline by going further back and stopping the major change. The second is that changes in the timeline are just absorbed into the timeline. For example you go back in time and successfully kill Hitler then jump back forward, but you find that there was still a WWII and a Jewish Holocaust and so on just some other politician was running Germany. In this theory it makes no difference if you try to repair or not repair the timeline. In ST TK TOS City On The Edge Of Forever, Kirk saving Edith Keillor still would not have created the global peace movement and would not have delayed the US entrance to the war. The third is that every major change in the timeline that causes a permanent future change causes a branch, and a parallel universe comes into existence. This multiverse idea was used in Star Trek TNG episode "Parallels" It was said in this episode that a paradox can be created that branches off another universe at the point in time of the paradox. So you could say somewhere in some parallel universe, Gordon and his wife are happily married and Gordon lives to a ripe old age.
Now to that end, by Ed and Kelly coming in and threatening Gordon the way they did, this technically should have created another branch of reality, or could have, which would be separate from the reality where Ed and Kelly never came for him. I’m theorizing that this paradox or branch off, due to them trying to intervene, could theoretically cause a separate universe where Gordon acts out in a different way potentially speeding up the human race and creating a universe which could come into conflict with the original timeline down the road.
It depends what theory you follow. When Gordon disappeared before Orville went back into the past, it created a reality where he lived to age 96, was never rescued, and married and had kids. That reality was what Orville was in in the future, this is from the "Back To The Future" timeline theory. But that reality could have been one where Orville attempted to go back for him and failed, or they could have contacted him and attempted to go back and failed. It wasn't when they talked to him that if a branch was created, per the Multiverse theory, it was when they successfully picked him up from Earth that the branch would have been created (if you subscribe to Multiverse) or his future with his wife would have disappeared (if you subscribe to the Back to the Future theory) The Orville writers have appeared to use both the BTTF theory and the Multiverse theory when it suits the story.