They most definitely knew that you would use their clubs when flying other airlines....
Until Aug 2016? you did not need a BP, only UC card (if airside) to enter UCs, so UA may not have had a good idea of how much that was happening.
In my opinion anyone who prepaid for membership extending past November 1 deserves a partial refund or an extension of the old policy through their prepaid expiration date. ....
The policy was posted a year in advance, so annual members got notice.
Lifetime / multi-year membership has not been sold for 7-8 years? 2011/2012?
2 MM lifetime UC memberships were dropped in 2012