WoW is full of these vestiges when the minimum level was higher. Off the top of my head:
- Deathcharger from Strath needs level 17 to learn. There are probably lots of mounts like this. But you can get the drop at 10;
- You need to be level 15 to spawn the Hydra in ZF
- You need to be level 15 to spawn the Postmaster in Strath
- A ton of SL side quests have weird minimum levels (51-55) that probably made sense when SL was current and that was the minimum level you'd be the first time you were doing the campaign. But it didn't even make sense with the original Threads of Fate (now gone) at 50+ for your alts. Now SL is 10+ it makes even less sense. SL is probably the worst CT expansion for this and many other reasons.
There are probably lots of others.