Entities using alias patterns with tokens of referenced entities are not updated.

This seems to be working for us. So if someone can review, maybe add some more tests?

Just discovered that this patch actually needs the core patch mentioned in https://www.drupal.org/project/drupal/issues/2727667 →
This core patch solves the problem that when a batch is set in a submit handler for a form entity, the subsequent calls to entity save are not callable.

Nice work on this, left a few comments. I have some serious concerns about performance here.

I maintain and help maintain sites with 100'000+ nodes (multiple times that, actually). imagine a term getting renamed that has 10'000 nodes referencing it. that will not end well, to put it nicely.

This is a hard problem to solve.

It also relies on batch and assumes all changes happen through the user interface.

An alternative might be to switch to queue based processing, that would take longer to process for cases with only a few references. So maybe a mix, if you detect more than lets say 10 references then push it to queue or something.

One option would be to publish and maintain this as as a separate project. While right now everything is add within the existing methods, there isn't really a need for that, this logic can live anywhere, it can just listen to entity saves on its own and call out to Pathauto. That would allow to document those limitations and people that are OK with that can install and try out the module, it could also be an alpha/beta release or whatever. As maintainer of Paragraphs with many, many installations, I need to be a lot more careful.