Yes, it is possible they may have openings for a walkup but I would not expect to drive in the MK area resorts and get in without a dining reservation. I think there was even a period of time that the MK area resorts, may still be going on, where only resort guests can mobile order. The popup message was in the
MDE app and may still be, it's been a few months since I was at the resorts. Of course, you're guaranteed to get in if you aren't driving to the resorts at MK and it's a toss up at AK. You might and you might not. I'd keep searching for an ADR or try another location.