The bug

When normally creating a debug world, the player is put in spectator mode: they can look, but can't touch. In the 1.17 snapshots, this is still the case.

However, now, the game mode for a debug world is not shown as "Spectator" on the world creation screen. In previous versions, this was correctly shown as "Spectator".

When generating the world, as said above, the player is put into spectator mode correctly.

This issue relates to MC-205076, but I am reporting it separately, as spectator mode is not part of the order described in MC-205076. Additionally, the text shown on the world creation screen is different than the actual behaviour, which is not the case in MC-205076.

How to reproduce

1. Open Minecraft -> Singleplayer -> Create New World -> More World Options...
2. Hold down the alt key (option) while toggling the World Type button, until you reach Debug Mode
3. Click Done
   The Game Mode is shown incorrectly
4. Click Create New World
   Your Game Mode is Spectator, as intended

Additional information

A screenshot demonstrating this issue has been attached, taken in snapshot 20w51a: