While alternative app stores operate independently and are required by EU law, Apple is still in a position to exert some control. This became apparent a few weeks ago, when iTorrent users suddenly ran into trouble when installing the app.
Thought this was an interesting story, since it’s pretty analagous to the recent Android situation, with third party app stores being enabled to some extent, but the company retaining ultimate censorship power.
They recently (two days ago) did a massive revoke on the paid certificates. All known sellers got hit with the massive revoke and it is at the moment a bit of a mess.
Rumor goes that Apple also hit actual developers with the revoke hit. So curious how that goes.