I don’t think it is possible to catch a lightening in the bottle twice. I think Deadfire is a New Vegas sprititual successor, and it just doesn’t work as well as it did the first time around.
I think that a lot of appeal of Fallout isn’t in Wasteland - yes, both are post apocalyptic wasteland settings, but a lot of charm of fallout comes from its interest in society, satire, humour and retro sf feel. Playing Wasteland2 felt different. What I am trying to say is: I feel like themes and world of Wasteland is different enough, to not really be a good candidate for a Fallout knockoff. I would be greatly disappointed with Wasteland2 if I expected it to be a fallout game, but I enjoyed it as it’s own thing.
The PoE&Tyranny releases felt a bit too safe for me - not that they were not ambitious, but appeal of Obsidian games was always the creativity and originality. Deadfire feels almost... formulaic. We have seen those ideas before, and unfortunately in many cases - done better. Better dungeons, better faction system, better companions, better crit path. While there are some games I would like to see sprititual successors too (like Alpha Protocol) I feel NV is too good to be repeated. Unique mechanics, coming together with a unique setting and story.
Hoping that the secret project will be the fresh new idea, we are waiting for.