You are correct; some do and some don't.
This is exactly what I did with my kids last August. I had a bunch of Marriott gift cards that I wanted to use for our tickets (charge to the room), and had found great deals on getaways (through Interval International; we're owners at Marriott's Ko Olina in Hawaii). So, I called around once I found where we could stay (Grande Vista one bedroom and Sabal Palms two bedroom). We could charge our tickets to the room at the Grande Vista, but could not do it at Sabal Palms. I booked one getaway at Grande Vista (and we just made due with the one bedroom having my son sleep on the sofabed and my daughter and I in the king bed) - then booked another two consecutive getaways that started 4 days later (getaways are 7 days, but it was still so much cheaper to leave early - each week was only about $300 total) at Sabal Palms. We stayed a total of 15 nights, leaving early also from Sabal Palms, but spent less than $1,000 total on lodging so it was still such a great deal!
The best deal was charging our 10 day park hopper with water fun & more tickets (3 of them) to the room and using gift cards! It was a super cheap trip, and a great way to use the gift cards for Disney tickets!
I had called around, and don't think there were many Marriotts that let you charge tickets to the room.