Makes sense imo. The solid wall to wall Winter's did basically what you described. High latitude blocking helped mitigate what trips the MJO made through the warm Phases. In some cases, it would go either low amp through or COD and come back into cold Phases( SST'S were supportive of that then).
My guess is as your's, in that the MJO will make it back to warm Phases at some point as the SST'S are still supportive for that to occur at decent Amp.
As you noted, the -QBO should help. Also, NATL SST'S have became more favorable in supporting a -NAO.