They haven't really mentioned a replacement. There may not be a direct replacement. They may just be stepping away from babysitting/date care service.
There are some fairly specific economics at work. You have to have at least 3 staffers at all times, which creates a specific ratio potential. This would be 3 staffers regardless of kids signed up, so it could be 3 for 5 kids, or for 45, both of which would be safely within any ratio defined by the State of Florida for this kind of thing, given that it's 3-12 and required toilet training.
Any additional character visits is additional cost for staffing, with fixed cost.
Many activities are just going to be a marginal cost per child, although there may be some savings if you're doing something with 20 vs. with 5.
What they were charging on an hourly basis, assuming 5 hours of use, with dinner, wasn't outrageous. I'm not sure there's serious price-dropping possible or manageable. I suppose you could book specific time blocks and just pay hourly, but that might also be a scheduling issue with staffing and demand.