Someone on the discord just spotted this change to the IC alcohol rules.
“If you want to exchange anything with alcohol while in-character, then please get in touch with us to discuss that.”
That sounds like it will need a bigger announcement (which I imagine is coming very soon).
Adelaarsgilde was on the fence about whether to sell alcohol anyway, so this probably tips the balance for us.
Sounds like it’s not a big change, exchanging can still happen, it’s just that PD would like players to get in touch so they know who is doing it and on what scale. Matt has updated the wiki entry above slightly to try and make that a bit clearer.
I think it’s possibly an old custom that’s being made a bit more explicit, I remember getting in touch with PD back when an old group of mine ran a small bar. 
Matt’s posted a clarification about this on the Empire FB group
“There isn’t a big announcement coming - I just want people who are exchanging alcohol for IC money to get in touch - it’s just so we know who you are and what you’re doing. I’ve updated the wiki FAQ to make that clearer.”
And the email to contact about this is matt@profounddecisions.co.uk