OP here. Sorry for the delayed response. I seem to have picked up "the crud" from my travels and it's knocked me totally out of commission. (At least I know I didn't pick it up from the bus floor - ha! I had the start of it before that.)
I did write Disney (from the airport) -
We opted to take the bus primarily because we were in such a state of shock that we didn't know what else TO do. All I had in the back of my mind is "If you miss the bus, you're SOL and Disney won't put you on the next one." Rationally, in hindsight, obviously they would have accommodated us somehow - but in the moment, when your choices are "sit on floor" or "miss last flight of the night" things get a little murkier.
Luggage under the bus had nothing to do with it. I had all of my carry ons with me... you know, on the floor.
As far as compensation - honestly, all I want is to know "next steps" if this happens again. I'll be on DME again within weeks and I'd like some recourse. I don't think $100 (equivalent to less than a one day ticket) would make heads roll, nor is there a monetary price that can be put on this sort of gaffe. Fastpasses won't fix it, this isn't a "time in park" issue, kwim? (Certainly a lawsuit hasn't even crossed my mind - this is a "risk" item in which nothing bad happened, just want to make sure it doesn't happen again!)
Safety is supposed to be one of Disney's "keys," followed by efficiency, but I fear the two have been flipped recently. Of course, statistically speaking, I was probably safer on that bus than in a passenger vehicle... but that doesn't make it okay.