I've called the hotel and the gist of their reply was: "This is something Marriott making us do. We dont have any hand in this. Marriott is sending emails to guests who were affected so the guests are aware in advance. Would you like me to transfer you to them?"
Since it was of no point to continue that conversation I had her transfer me to main reservations. After a quick 2min hold I got a pleasant agent and learned that:
a) The fee is not showing up in one of the views she is looking at (if I understood her correctly), but it is standard fee for "resorts", even though this hotel is not marked as resort.
b) They have ability to review the call (since the reservation was made on the phone to use TP)
c) When they review the call they can see what messages were "flashing" on the screen and if the person making the reservation made me aware of the fee
d) If the "flash" notification was there and was not announced - the department of that "person" will be billed
e) If the flash was not there and fee was added later - the hotel will be billed
I received a case number that should be reviewed/resolved in 5-7 business days. Holding my breath....