I'd say it's 50/50 whether we will get Willow. Alyson and Alexis are still close to Joss and IIRC, were the only two main cast not to put out any kind of statement and she dropped out of a few interviews for a Buffy book which didn't paint her in a great light. There is a possible chance with Spike and Angel...where they could either have got the Shanshu after all or they could be de-aged. I know James is willing if they can do it in a plausible way but not sure about David.

The reason for the cancellation wasn't viewers as it was one of the reasons so many signed up to Paramount +. What doomed it like others was the strike as the delay meant it would take too long to write and then film.