They won't be patching this to add features or MP. Apex is basically a tech demo offered for free to get a variety of people (a lot new people to Forza) playing it on a variety of hardware configurations in order to get feedback. Remember they are 8 releases into this franchise and have only ever had to support 3 hardware configuration and 1 pad and wheel protocol.
What it will mean hopefully, is that Horizon 3 and FM7 come to PC.
Oh so I take it then that FM6 isn't going to end up on PC after all... Damn thats a shame, hopefully the demo shows there is serious interest for Forza on PC and FM7 does indeed end up on PC in the future..