I spoke with tech support. 6 family members is the max. I have 7.
My feature request is that Apple offer 2 tiers of sharing... a household tier and then a media tier. The media sharing is probably what caused them to make a 6 user max in their family sharing plan. There is a cost to media they have to limit.
However I want to use the family sharing to find phones, find friends (kids), share apps, manage billing for my kids, share calendars, share photos, share icloud... All of these things should not have a 6 person limit. Apple should want us in their ecosystem and our kids too. If we decide to buy movies or music we should pay a higher fee... a good comparison is netflix has a 2 screen simultaneous limit on their $7.99 offering... with a big family I upgraded to their $11.99 offering for 4 devices to watch at once.
Apple should allow 10 or even 20 users in a 'family management' plan that's free... to get us into their ecosystem...
Then they should sell 'media sharing' packages of 5 users in those plans. I then get free 'family management' for the non media stuff.. and I buy 'media share' licenses in packs of 5 for say $10/month. That would keep me buying apple devices and using their ecosystem.
Now i have to go look at office365 and google as an alternative for everything and I still have an app issue where one of my family members (aka wife) will be buying her own apps.