It's probably not gonna happen. They're never going to replace 13 crownstore exclusive items with just one so the only other option I can see would be introducing yet another crownstore item that the other feed into. Going by the pricing scale for the GMC stations, it'd be about 10k crowns. Don't get me wrong, I figure they'd do it if they thought they could get away with it, I just don't think they could. If people have already spent, what, 52k? on the stones plus probably another 15k on a house big enough to put them in, I don't think they'll be thrilled about spending even more on them.
cant see the point in mundus stones for houses, how often do we change them and if you want a different one save it in armoury build, plus they are a total rip off and not visually appealing in many houses, it would be nice if they did that though like they did with grand master stations, what would be even better is if they were purchasable with writ vouchers like the stations are.