With TWW early access chromie time got extended to 70, but Cataclysm restriction did not.
It’s now possible to fly at level 10, so the Cataclysm restriction should probably just be removed completely and you should be able to do both Classic and Cataclysm content at level 10.
Confirmed at 61. Just tried it, not available, only greyed out Heroic is, says “You do not meet the requirements for this dungeon.” But it does not tell me what the requirements are.
For what it is worth, Chromie time has done lots of screwy level restricted stuff to Classic and Cata dungeons for many years now.
Edit:
At level 64 now I only have access to these dungeons.
That’s it. With level ranges 10-71. Prior to 61 I had ALL Classic (after a certain level anyway, some were not available right away at 10) dungeons listed, all level ranges 10-71, but now in the 60s, they are no longer there. Same issue as pre-pre-patch, just 10 levels higher.
Only been annoying the player base for many years now. Who knows if or when it will ever get fixed.