I feel like a broken record, but here I go again: Fairphone never promised anything, ever! They can’t! Nobody can promise any of the things that people keep claiming that Fairphone has promised.
Clearly more than enough people trust them, otherwise the demand wouldn’t be higher than the supply and therefore I wouldn’t worry about that.
None of the alternative OSes are officially supported by FP. They don’t have the resources to support alternative OSes. Ubuntu on the FP may be officially supported by UB Ports, but that doesn’t mean they get special treatment from Fairphone.
If nobody used it the community wouldn’t have ported it.
Completely.