I seem to recall this is by design, to teach you to make edits. Then you have to use the heavyweight edit UI even when you genuinely only want to change tags.
When you get to 10000 rep, you get the retag link back (hidden, but in a conveniently placed location).
Since this state of things was decided, two things happened:
- There are more and more SE sites, so more and more people already know how things work, thank you very much, already have the copy editor badge on another site, and don't want to go through UI hassles again.
- Now anyone can suggest an edit from day 1, so all 2000 rep changes is that the edits are unsupervised. Editing is no longer a new feature you get at 2000 rep, so it no longer makes any sense to “teach” it.¹
Fortunately, this is a client-side UI annoyance, so it can be fixed with a browser script.
¹ Approving edits is a new feature, but one you won't discover unless you pay very close attention or until you reach 10k.