To be quite frank, this whole debate is pointless.
Arguing for "classic" orientated aspects of the game that are gone, to be re-introduced into the "current" game, is a waste of time. The majority of current players don't want it. If the developers introduce such against the current players wishes, they'll vote with their wallets.
Separate "classic" shards should be offered, if there's sufficient demand. Most sensible "classic" supporters would prefer separate shards, simply because mixing the play-style they prefer, with what's currently available, would be like mixing oil and water.
Although suggested that there will be an answer to the "classic" question by the end of the year, I don't see it happening. I believe the focus on boosters has pretty much killed any "classic" offerings.
Ok, so they could launch it as one of the boosters. I can guarantee here and now, there will be wailing and gnashing of teeth if that happened, because the current players would claim they're suddenly being neglected, albeit in a one-off offering to encourage a potentially sizeable group of players back.
Suffice it to say, I'll lay good odds on there not being a classic shard realistically being on the table. Hot air. Nothing more.
I suspect Cal wishes he'd said no as soon as he was prodded about "classic". I would much rather someone say "No, we're running the show and we'll do things how we are doing them", than "if" or "maybe". So long as there's a carrot dangling, people will try to grab it. Providing no definitive resolution to the question, only annoys both sides.