Obsolete Consoles

They'll most likely do what they did for the Xbox 360 and let it live on until it just doesn't need to be alive anymore. I feel like this console coming out will be more connected with the Xbox One.

I would say no, Since the Xbox series X is having Backward Compatible with Xbox 360 Games and Xbox One games I think that it will be support for a few more years after

according to the most recent background I can tell you that no, xbox 360 had support for all this generation, so we can know xbox one will have support even after the departure of the new xbox, although it may no longer get as many games as it happens
in changes of Generation

I think not and that the first two a three years Both consoles together exist.

They won't become obsolete, the Xbox 360 was still supported for years after the Xbox One launched in terms of both third party games, and dashboard updates. I wouldn't expect too much in the way of brand new titles, but the consoles will still work and
I'd imagine they'll continue adding Xbox One titles to Game Pass for years to come. The plan seems to be that all Xbox One titles will work on the Xbox Series X, so I would be shocked if we don't keep seeing things added to Game Pass.