My experience at reservation time is after clicking to reserve you are taken to the preference screen (unless you have saved them) after you select your preferences, the next page usually reads:

Nonsmoking, King Bed Guaranteed
Nonsmoking is not available, King Bed Guaranteed

Also on this screen is floor or other special requested "are noted...please inquire at checkin"

My point is this...it tells you at this point if it was guaranteed or unavailable. I have had an experience where a confirmed reservation was changed, and that hotel had to pay the piper. (Elite Gurarantee plus ended up walking me)

I have never seen it say noted...