Initially (2023) it came from the same place at lot of the Glastonbury stuff comes from.
I did, however, end up locked in conversation with someone who'd spent a fair bit of time with the band a few months back. I decided to ask him (after half a dozen lagers) assuming he'd tell me where to go, but he essentially said the same thing had been said to him... directly.
I was told likely solo and/or TLSP 3 when I first got the info. The conversation I had a few months back suggested that Alex is really keen to go down the film score route (not to say solo/TSLP couldn't still happen in the coming years).
I suspected it myself tbh during The Car tour. Various subtle signs. When they finished on Perfect Sense in Dublin it felt a bit like a moment in time, to me.