Nothing should happen, you should just get a CEL.
Does it have an IAC (idle air control) valve? if it does, find it, take it out, clean it, put it back and try again.
But yeah, what max says. When you unplug it, it stops metering from there and starts from MAP sensor instead.
thats if has a map. I know on older (90's/early '00s) toyotas, if you unplug the maf the car will just stall out. I have no idea what bmw's engine management strategy is
Got it
It does have a ICV, I can use carb cleaner on that, yeah?
It has a fail safe where if the MAF is gone it reverts to a safety tune kinda-thing
In other news, my ASR and ABS lights came on on the way in to work this morning, restarted the car, and they're gone.
All fixed!
Getting my morning poop in! Feels great!
I can't wait to get this Thursday OVER!