Sorry if addressed in the link (I'm not willing to visit Twitter) -- but, like, actually McDonald's themed? Or are they just sponsoring a show (like P&G, etc. have done for ages)?
If the former, I guess there's some precedence with the KFC visual novel and Isekai Izakaya and such, but that still sounds pretty weird...
Edit: I went back and checked and it looks like McDonald's was also a sponsor on the show I remember P&G from (i.e. season 1 of Bleach), so there's precedence for them sponsoring Studio Pierrot's shows too -- I just don't usually pay that much attention to it, I guess.
The word "matrix" literally means "womb" in its older sense.