I don't believe that Obsidian will be using CE3, I believe they will use the same engine as FO4/Starfield. I don't think they will be tasked with pushing the technology further now any more than they were tasked with it for FONV. They may extend it a bit (like how they added weapon mods in FONV) but their focus will only be on releasing an entertaining title quickly (and I think the whole idea to bring Obsidian in was a great decision on Microsoft's part). I think the other group will be tasked with moving the engine forward for FO5 and ESVI.

I agree with your assessments of both FO76 and Starfield. I played them both, but only because I got free accounts for both of them, FO76 on Xbox and Starfield I got a month's worth of free Game Pass and played it via streaming. They're both terrible. FO4 was also pretty terrible, imo. I've enjoyed replaying the Oblivion remaster more than anything they've done since Skyrim. So, I'm also not holding my breath for what comes next and you might be 100% right, but I do like the Obsidian angle for this reason, if nothing else: the competition will put Todd's incompetence on display. Todd's not the only game in town now, and for the first time in over a decade, he might be feeling some heat.

Edit: if they do use the FO4 engine, I hope they correct every stupid mistake they made in FO4 the way you can do it yourself with mods.