It's not a bait and switch because the old version of the software that was released with the old license can still be used as such. If you call this bait and switch then I suppose this means that you somehow feel entitled to future versions of the software having the same license, forever.

That’s the thing with software, you can automate most future updates, with LLMs and whatnot.

Also, the initial software probably didn’t have a lot of known cves when it was sold.