Nothing happens to the Ralph at this time. Ralph Engelstad is gone so we don't know his opinion on the current state of affairs, but he did threaten to halt construction of the arena back when it was being built (around 12 years ago IIRC). UND will continue to use the Ralph, as I'm sure he would've wanted them to given the present circumstances (NCAA changed the rules after his passing). The logo at center ice and other non-permanent logos were changed for this year. However, the logos in the floors, all over the outside of the building, and on the seats, walls, etc. will still be there. I believe there is a retirement schedule for certain, less costly to remove logos, but I don't see the logos in the granite/marble/whatever floors going away any time soon. Also, I believe UND is allowed to keep using the Fighting Sioux WHCA and NCAA championship banners due to historical significance.
The main category of people offended by the moniker were caucasian, liberal arts faculty members. One really can't expect them to think rationally in these sorts of situations.