As a dedicated Alton Towers community I'd hope you would hear it here first if that was true!
Every coaster comes to the end of its life at some point, but Spinball, and any Maurer spinning coaster is far cheaper to replace in parts than other coasters.
It was only a few years ago that large parts of Dragon's Fury were removed and replaced due to excessive wear and tear, and the ride vehicles are cheaper to replace individually than a larger coaster train.
I feel there is still plenty of life left in it, especially as it is so popular. The removal also depends on whether the land is earmarked for development - but there are plenty of other vacant spots to install new attractions first.
I was wondering why it would be removed, because there is alway a queue for it. If it was removed though, I would still say it would be a good investment for Oakwood. I do like the ride as its a different dimension to the other coasters in the park and it would be sad to see it leave and not go to another UK Park that needs something to draw crowds back after the 2020 season.