No.

Sorry to be so brief about it. This is a convoluted pseudo-solution to an unknown and unconfirmed problem that has a simple solution even if it ends up being a problem (just rename the sub-roles).

You also have absolutely zero indication that would promote thinking that it'll become a problem, while you do have indication (healer sub-roles, melee vs caster) that it won't become one.

And, more importantly, what you're describing is more or less what WoW tried in early-ish TBC until right before WotLK release, and it was abandoned for a reason. It was really cool flavor-wise (IMO that era had the best class/spec implementations WoW ever managed including actual tank warlock fights and all), but it didn't work well for balancing the game or designing fights. Just consider, from your three examples given, that whoever is "anti-magic tank" would naturally be the superior tank in ~all existing content, as current fights are quite strongly favoring mass-magic damage, plenty of them even on autoattacks. And that's just one example of why such a setup would not be workable, and incidentally one of the issues WoW also ran into, that it forces re-implementing ~all existing encounters.

Also note that your 6 individual requirements work just as well for just MT/OT splits as indicated during fanfest.
(we know very little about it, but from what we know, that'd fit those 6 requirements so I guess this means you're inherently seeing that as a possible implementation of your solution, yes?)