This is something I would like for covenants. You can switch, but only once every week (or every two if one week isn't MeAnInGfUl ChOiCe enough) and every covenant has separate soulbind/sanctum/followers progression (+ of course you can't use transmog from inactive faction).
Imo choice every 1 (2) week, but without chance to switch is better than just puting it behind some paywall like Azerite.