Considering a split CBR/Dolphin stay -- do you need to tell Marriott your kids' real ages?

I’m considering a split stay – we already have 5 nights booked at CBR but instead of moving to Universal for the following 3 nights (we’re tweaking our road trip plans to arrive in Orlando 5 days earlier and start with Universal) I’m now looking at moving to the Swan or Dolphin and enjoying the walkability of being on the Boardwalk. There’s a kids-eat-free (at 2 restaurants) deal available for our nights at the Dolphin… for kids 9 and under. That rate is $5 night more than the Member’s rate, and I’m not certain we’ll be eating there.

I will probably decide to go for the cheaper room rate or maybe use Bonvoy points, but it made me curious. If someone booked the kids-eat-free deal and “accidentally” entered a 10 or 11 year old as 9, is there any information shared between Disney (which has their real birth dates) and Marriott if that someone doesn’t load the Marriott reservation into My Disney Experience?