I can easily see them sticking to the permanent guest-host format. They can be so flexible with it, and as others have already said, it allows for all kinds of Paramount stunt-hosting for big new Paramount+ launches, major movies or whatever. And while I'm sure there's a steep learning curve for the production team each time someone completely new comes along (not everyone can read from a teleprompter, or conduct even the fluffiest of interviews with a guest plugging something), what they'll end up doing is re-using the same people once or twice a year who definitely are able to do it.
It's not the same thing, but in the UK, Have I Got News For You has used guest hosts for years now. In truth, there are a handful of names who probably pop up once a series alongside a few new names. The show runs smoothly.
So all the regular correspondents probably end up doing 2-3 weeks across the year each, with guests the rest of the time. And the other thing is that there's always next week to look forward to even if you don't get on with the current host. If James Corden isn't your thing, you'd long bailed on the Late Late Show. But if it was someone new every week, you'd perhaps give the show another chance next week even if you hate this week's host.
Some will be good; some will be less good. But there's always something new. And Comedy Central gets to release loads of press releases and get coverage every time they have a new batch of names.
Personally speaking, I think this has breathed new life into the show.
Adam