100% yes. The fact that they let 4th yr players select whichever plan is most favorable for them but not 5th is the least defensible thing I've seen them do.Because there's no CBA.
It has to be an unspoken (if only for discovery purposes) understanding that they will lose this year (and probably next) on anything remotely unfavorable to a players' earnings.
The only thing I can think of why they did it this way is to make 6th year lawsuits less frequent.