> rather than universities writing an open alternative they share with each other for free

That already exists [0], and is actually reasonably popular.

> the SaaSpocalypse is coming for them - it seems it is simply that LLMs will be used to exploit it first

I doubt it, because enterprise sales has nothing to do with how good your product is, how expensive it is, how easy it is to administer, how secure it is, etc.; it only depends on how good you are at enterprise sales. I mean, my university is Oracle-based, and I'm pretty sure that you could get 3 random undergraduates to write something better, so I don't think that LLMs writing better/cheaper software will make any difference here.

[0]: https://moodle.org/