Oh fear not, limiting filter list updates to addon updates is a huge problem. For those users who rarely restart their browsers it's even bigger of a problem: updating the addon (for the up to date filter lists) also means that all of the already loaded websites will lose the filters until you reload them, which is both not obvious to be needed and very painful, when you are using your browser for other things than consuming.

Also, does that also mean that custom filter lists are impossible anymore?

Besides these, also take into account that approval of addon updates can take a long time, quite often days, while the filters need to be updated more often (once or twice a day) for websites to not break for the majority of the users.

Yes, thinking about it, I still confidently think that chrome's changes are unacceptable and are dealbreakers, and google is very clearly trying to curb content blockers with whatever tools available. Fortunately I don't have to use that garbage anywhere.