Media Molecule is a small studio with a lot of people who comes straight from University. So unlike the other studios filled with experienced veterans, it's very cheap to keep running. Sony closed Evolution and Liverpool because they were losing a huge amount of money every year since a lot of time ago, and it is not the case of MM.
In addition to this, the LBP games were a huge success, I assume they generated a huge chunk of money that would keep the studio running for many years without any extra funding needed from Sony. And considering Minecraft, LBP or Mario Maker success, Dreams may be a hit too.
So Sony should be confident with them, and allow them to do whatever they consider. They may be crafting another sleeper hit. Doesn't matter if it is artsy, innovative, niche or doesn't sell a lot, because it may add quality and variety to their catalog, something that always helps indirectly to enlarge your console userbase and influence other games. Like LBP did influencing New Super Mario Bros or Mario Maker.
It doesn't make sense to ask Sony to close one of the most talented, unique, innovative and (very likely) profitable studios they have, or to cancel their main project that looks very interesting.