I don't think it's needed but I would love to see them do it right. I love the housing system in Final Fantasy 14 and I loved the one in Wildstar. They would just need to take the time to make it a lasting system and not tie it to a specific expansion. I think as it stands now though it would be really hard to justify the work required to make it. Sure you could argue a lot of the assets are already there and they would just need to build the actual housing system but even then I am sure that requires a ton of work and people are going to see it as a waste when that work could go into a raid or something else.
Personally I want it. Once the band-aid is ripped off the possibilities for it are massive. they could literally create an entire professions for it or just add things to the existing ones. It is also entirely optional and only the people who really want it can bother with it unlike the Garrisons. Honestly anything to make the world more fleshed out and feel lived in is a good thing IMO. i just don't see Blizzard ever doing it because of how the community at large seems to view them. Maybe i am wrong and the people on forums are as usual the vocal minority but I just know how Blizzard seems to work and their art team seems stretched very thin as it is.