From past experiences, I've always gotten 500 points with zero housekeeping done. As in they don't enter your room at all. It's as if you put a "DND" sign on the door. However, if needed, you can call them to get more toiletries for example.

I don't see the point of asking new towels (or ask for linen change) if you go for MAGC. The whole point is for the hotel to save money on laundry, get a few bonus points to the guest and oh yeah, help the environment a bit?