I've had this issue on a CAS/HT box, which also happened to have the mailbox role as it was the first-built E12 server. Once I had my CCR mailbox cluster running, I wanted to remove the mailbox role, but couldn't due to there still being a PF replica.
I ended up having to call PSS after trying everything listed in the article above.
I'm still not sure exactly what fixed it out of these two:
(1) installing Update Rollup 2 for E12
(2) recreating a mailbox database ( I had previously removed all mailbox DBs and stores on the server)
I assume it was the latter, and this enabled the PF to replicate properly to the new mailbox server.
Thanks for the post though, it's nice that others who encounter this problem will be able to find all this information in the one place!