It's too early to tell, and anything can happen. But there is an excerpt from an interview with Yoshi-P that implies a slight possibility of instanced housing:
“This plan actually started a while back as we had received much feedback from players who would like to
have their minions roam free in their houses and others who had wanted to raise animals in the game,” Yoshida recalls. “We reached the conclusion that we’d need to prepare a new mode to achieve this, as it was
impossible for our housing features to accommodate these requests."
Source:
https://www.pcgamesn.com/final-fanta...land-sanctuary
Disclaimer; these are not confirmations. But the statement implies minions roaming private housing was part of the initial request and seeing as the last bit implies the island sanctuary is an alternative to the current housing, there's a chance this might be their try at instanced housing. He also mentioned Animal Crossing in the interview, which is interesting, because each island in animal crossing is basically an instanced housing, and up to 7 visitors can visit at a time. 7 plus you is a full party. That's enough to host passing visitors or some casual friends.
As for people who have more than 7 friends to constantly lounge together with at a house, massive role play hosts, or FCs, standard non-instanced housing is still here for you, but for those people who just want a house they can call their own and bring a couple friends over, this would be a game changer.