Ok offer another perspective. My partner is SQ Solitaire and I am offered spousal privileges which many are the same. We both access saver economy awards whenever M class is available for sale. In most years that is usually available as it 4th highest fare. However this year it had been difficult to get these, particularly between Australia and Singapore (and SIN and Europe).
As for waitlists clearing, hahaha, used to have no problems, this year very difficult. And usually only if M comes back into inventory anyway. We’ve had dozens of waitlists that have not cleared. This is for the top publisher tier in the program.