WoW, I come back just to read that people are really thinking Blizzard would abandon retail or make an HD classic+ instead of a retail revamp? That's absurd.
Classic servers usually have a hype spike and than die out, if anything they should make them a seasonal thing with a server transfer to retail at the end once they are finished with wotlk/cataclysm's last tier.
Besides that, Ion already said they will have to do a world revamp for RETAIL in order to have a "living world" (which btw was a codename already used during I think Shadowlands development if I remember it right, as we had some datamined strings refering to it).