That is correct. We have pivoted to only marking fields that are optional as such, while all other fields can be considered required by default. The logic behind it is, most fields are required so it cuts down on noise.
There’s pro and cons and endless discussion online amongst the designer community, but that’s the approach we’re taking.
I think we decided to drop the other instructions, as they weren’t very useful.
The username instruction used to be:
I think everyone is by now aware a username is an unique identifier without spaces.
That’s a worse issue. I just tried though, and it seems to work as expected. A recording would be helpful to see the issue.