Never heard of it so naturally never tried it before (granted I also don't really have a VIP level account in a casino), but in paper it pretty much makes sense. I mean this introduces the capability for a user to migrate to a new casino, all benefits attached after all. Just that, I don't think THAT makes sense in the casino side. Like, a VIP status was MADE with money. If that was transferred over, did the casino it transferred over make money for making him a VIP? Nope. They just gave out a free one lol. If there was talks about transfers and payments then yeah maybe, but why the hell would a business losing a customer pay for them? That'd be a big joke lol.
I haven't tried it either but I already heard of it. I think this only applies to the new casino that has the same owner as the other, or they have a special connections with them because like you said, there is no benefit for it as a casino owner but the benefit are only on the players side.
It is okay to not have a VIP level account in a casino. They are costly anyway and then some gamblers like you might only be playing for fun sometimes, so you can care less of this and the other stuffs inside a casino. As a completely new casino, maybe they have what you said there or a user needs to pay first before he can transfer his VIP level from the other casino. Maybe some players would like to avail this but there are some who likes to start again from scratch.