I agree with you that the curb cut shown here is unfortunate.Looking at the renderings again... I still think it is CRAZY that there are cars involved in this. It should be ped and LRT. It will be a nightmare to get into and out of that ramp on game days.
However, I don't think the primary use of the Interchange parking garage will be for gameday parking. For one, it's only a couple hundred spaces. Secondly, I figured its primary use was for employees of Hennepin County, Covanta, Met Transit, retail tenants, etc. and storage of vehicles for those same organizations. I know there is a public parking component to this, but I highly doubt it will be advertised as a gameday amenity. Even if so, it would be 100% full long before any real crowds arrive on the plaza or in the surrounding area. Getting out during the post-game crush, yeah that could be tough.