But that issue has nothing to do with the question of whether the "filter lists" could be updated dynamically without store review. It's asking for a way of programatically triggering the update to the latest version of the extension in the store.

That feature request being fixed would do nothing to enable updates without store review. And likewise the feature for doing updates of the ruleset without a store review already exists but is not used by UBOL.

So the link doesn't actually support your claim of it being a limitation of MV3. The link is just irrelevant.

The FAQ hints at why UBOL doens't make use of that feature, but doesn't actually state it outright.