More "features will land", not necessarily extensions. They have limited internal extensions API because several of their features were implemented with bundled extensions, but it doesn't talk about extensions/addons themselves.

And, yes, there's the "ad blocking" issue: https://github.com/mozilla-mobile/fenix/issues/96

What does it actually say? The requirement is "Integrate/support for different adblock lists (see Focus)".

So you can have certain ad-block lists, but not the actual customization and not uBlock Origin.