Why not have a separate community for alumni of the programme? Then you are simply ‘graduating’
It makes sense to keep in touch and create a network even if you are no longer providing them with services. It only needs to be a place to stay in touch, so no budget required.
On a related note, I once had an idea for a REVERSE fitness programme. You could only join if you could prove how unfit you were, but you would at least see posts by the community, join conversations and see incentives to get fit. As you got better, you were given rewards that sounded negative (e.g. “Wasted 100+ hours on a stationary bike”) that were in fact gains. The kicker was that at a certain point you were literally kicked out for being TOO FIT.
The domain was unfittojoin.com (I think I gave up the URL)
However, maybe a fun idea to borrow in there somewhere?