When I fail a level and retry, it's understandable that the pre-level text doesn't repeat; usually you wouldn't want it to.
But if the player wants to see the text again -- perhaps they're a new player learning the ropes and they want to look again at a trick described in the text; perhaps they're a tester giving suggestions for improving the text -- if they exit to menu and choose the same level, the text should repeat.
It not appearing again after a full exit to the menu sounds like a bug, to be honest. I don't remember if I intentionally wrote it this way or not, but yeah, sounds like that should be changed.
I also wonder - middle click currently does nothing special on the preview screen. Perhaps a change is possible here: Middle click does the same as left-click, but never skips the preview text.
Commit 1952E82 addresses both of the above - preview text will be shown again if you've exited to the menu; and you can middle-click instead of left-click on the preview screen, which has the same effect as left-click but never skips the preview text.