New Premier iCloud as organizer vs iCloud sharing from Family Member

I'm the organizer for the iTunes family plan, my brother who is apart of my family sharing added a 2TB iCloud sharing plan months back for the family. I just upgraded our plan to Premier which also includes a 2TB iCloud storage. We decided to get premier so we can just combine it all together and my brother doesn't have to pay individually for the family storage plan and we get the other extra stuff premier comes with. When I go into the iCloud storage it still shows the 2TB shared from my brother instead of my own. The one I should have gotten from premier doesn't even show. It looks like it only gives me 2 options to use my 2TB storage individually for myself or join the family storage that my brother bought. It won't let me share my storage with the family.

How do I get my iCloud shared with the family?

If my brother cancels his family storage will it give them the option to join my storage?

If he gets rid of his is there a way to transfer his iCloud to mines simultaneously so he doesn't lose his data? He has over 226GB saved on there already for himself alone.