In his last interview providing summer previews, Scott Hamner referenced the S/L involving Adam/Diane/Victor. He referenced that it would be a great S/L and, interestingly, it was really a "tribute to Diane." At the time I read it, I wondered what the "Diane tribute" was all about....now, I guess we understand.
I do not think they will bring back the character of Diane. The "Diane tribute" suggests a finale for the character as well as the actress. Of course, TPTB are entitled to change their minds -- an entitlement they fairly over-abuse.
As for MW, I will miss her. She represented to me a "classic dayatime soup opera star" -- a bit overdramatic perhaps, but that is how they are directed -- she continually brought character, cunning and interest to her scenes.
I will enjoy her last S/L, and I am happy for her that she will be working with MM and EB, two of the finest -- a true tribute to Maura West, as well as "Diane."