First off you aren’t a moderator, and as you pointed out…the PROPER forum doesn’t exist yet, so this is the only place we can ask for it since it’s considered legacy content and fits the Classic theme in that regard. And NO it’s not too soon considering how long it takes for an expansion/patch to be in development before it’s ready, so the sooner we discuss it the better
And for the record, Blizzard themselves initially brought up TBC. This was over a month ago, so you’re a bit late to the party here 
Most of us who talk about the expansions here have done so based on the premise that Classic will remain in perpetuity as a museum piece just as Blizzard had promised us to begin with, and yes that means separate clients/servers.