I’m waiting for the furor over bigger bugs to die down before I report it
In the mean time, here’s a partial workaround: go into single-player first, make yourself an admin, turn on the debug HUD, and then go connect to your server of choice.
The debug HUD will stay on – in fact, you won’t be able to turn it off without going back into single-player admin mode – but it will be less functional than before. You don’t get the server FPS or the player count, for example.
Personally, I don’t think this is a bug. I imagine that they decided to restrict this to admins only because too many people were causing the server to send additional debug information to the clients.
Of course, it would be nice if they would give us a much more limited HUD overlay that only displayed the ping and (hopefully) server FPS, but something tells me this isn’t high on their priority list.