Having seen FO4, whether you love it or hate it, one thing is obvious:
Fallout is transitioning away from the originals. It will no longer be the series it once was, for better or for worse.
However...
I always felt as though Obsidian probably designed New Vegas with the idea that "this may be the last Fallout we ever make." The ending felt very dramatic to me, to the point where I thought "how on earth will the series ever top Lonesome Road? This is clearly the climix of the franchise..." I think Obsidian purposefully gave New Vegas such an ending in case that would ultimately need to double as an ending to the original Fallouts someday, once it became clear another Core Region Fallout would be impossible for them or unlikely.
I even once wrote up a post about symbolism involving ED-E. What is ED-E? He's Courier Six's constant companion, and he's the only evidence of Bethesda's Fallout being a thing. Eyebots are a Bethesda creation, and ED-E originally hails from D.C.. At the end of Lonesome Road, the symbolism with ED-E is kind of strong. Courier Six represents the original Fallouts, ED-E represents Bethesda. Courier Six is reliant on ED-E now and cannot continue on without him. Without ED-E, there will be no Lonesome Road adventure, and Courier Six cannot progress, just as Fallout cannot progress. However, by the end of it, you're given a sort of ultimatum. To save the Core Region in it's entirety? ED-E has to go. To save ED-E, the Core Region must suffer. The two cannot co-exist. It's so fitting. I don't remember if I brought this up before or not, because admittedly my interpretation is very melodramatic and seems a tad anti-Bethesda (don't mean it to be, wouldn't post here if I didn't respect the company, but it's clear they don't mix with the original Fallouts), but I've long noticed this. Aside from that, ED-E is the first companion within the Fallout series that is practically confirmed to remain with a protagonist even after the adventure is done. All endings for him involving completing his content and his quest explicitly state that he remains with the Courier and he does not go his seperate way like the others.
What's beautiful here though is that that ending? It was so perfect. Lonesome Road and New Vegas gave us everything we could've wanted from a Fallout game. It gave us a big decision, it gave us tons of control and impact in the world, and as I said, Lonesome Road was an absolute climix. Lonesome Road saw the most intense build-up and potential consequences we've ever seen. Lonesome Road and New Vegas itself allow you to make or break nations.
Do any of you really want Bethesda to pick a winner now?
I think in the past, a lot of us speculated on the canon ending because we wanted to see a "New Vegas 2." Just a working title of course and probably not within New Vegas at all, but a continuation that references the region and it's lore. We were excited to see the next Obsidian Fallout game and hear who won the Second Battle for Hoover Dam and what happened at the Divide, because there were tons of implications and possibilities.
Now though...?
I think most of New Vegas' fans would not be fans of the direction FO4 is headed towards, and if "New Vegas 2" were to be in the style of FO4, I don't know that we'd want to see another game. Me personally, I'd prefer the Core Region's ending was at the Divide between the Courier and Ulysses. And yes, I'd prefer it's ambiguous.
All I'm saying was....it doesn't get any better than that. Obsidian chose a fantastic way to end the Core Region's story. It literally went out with a bang. (even if you didn't launch)
I'm upset to see FO4's direction, but I take solace in how perfect the ending to New Vegas was. And for me? I think the ending is more impactful if we never revisit the region and we never make any endings canon. All of us can have our own ending now. We can finally stop the bickering between the NCR and the Legion, cause both Rangers and Legionaires can write their own ending to the Core Region. House and Indy can get along and stop debating whose better for the region, cause both are personal choices that each can imagine for themselves. Everyone's finalized head canon is now valid, whether you blew everything up or created a paradise. It's a great, great way to end the series of the originals, and I'd hate to see that ruined now. After all, it ties in perfectly to the ending words of New Vegas:
War. War never changes. Men do. Through the roads they walk. And this road...? Has reached it's end.