I don't know if they are making a loss with the WOF spins; if that would be the case they would have made other changes to the prizes you could win or even canceled it. Wetsuit is a great guy but I don't think he would keep operating freebitco.in with a loss also. Their sister site freedoge.in was closed years ago because they were making a loss on that, so I doubt that will the case for the main site.
I think freebitcoin will close the site if they feel they are losing money from the WOF rounds held for all their users, until now they are still operating meaning their income and profits are much greater than their expenses by holding free WOF rounds for all users, after all there are not many won the main prize in the WOF round and even now no one has shared their story in this thread of winning the main prize in the WOF round.
Freebitcoin will still continue to run, it seems, even though the price of bitcoin will increase and make the free spin income drop to 1 satoshi, they will also provide other prizes that their users can get so that they remain active doing free spins every hour, but actually there is a feature that is actually very unfortunate to be removed even though it is also to increase their income such as advertising, previously people could place advertisements on this site using banners but now they don't exist anymore. but it seems they are still quite rich because many rich gamblers are still active on this site.