Resolution: Compensation and great stay on different dates
Just an update for those who are interested in the final resolution.
I ended up managing to confirm 4 nights with points deducted. The hotel was overbooked on all 4 nights. July I checked in again with the hotel and they were still overbooked. I'd heard that some people received generous compensation - points compensation + comped night - and decided to explore the option. In the end the hotel agreed to compensate with 200,000 points and 2 complimentary nights on different dates. I wanted to complete the stay first before reporting back here, and stahad they last month that went as it should - full board and 2 activities per day. Conversations in person at the resort also all point towards the hotel actually being overbooked due to Marriott IT issues. Overall I'm very happy with the outcome and although wasn't able to stay during NYE I had an otherwise excellent time.