It would be nice if you could actually link to some of those posts (we like banklinks, right?), because when I was creating this I wasn’t able to find anything relevant (probably my search wasn’t good).
I searched again and found Using display text `|` in links does not auto-complete the selected note - #2 by WhiteNoise which is another post of you saying “this was discussed and reported other times”
Searched again and found Using pipe for alternative text does not autocomplete the link - #2 by WhiteNoise
It not a bug. It’s a design decision. Otherwise you could not easily write non-existing pages.
Maybe I don’t fully understand what the usecase for “write non-existing pages” is. When would you want to link to pages that don’t exist yet? I’m asking because I genuinely don’t know.
(Also this really feels like a bug because it’s so similar and yet not working the same as as ^ and #. If this is being asked over and over again, maybe this design choice is not as clear as thought and needs some rethinking/adjustment. Or maybe some easy-to-find tip somewhere that you should press TAB for that case.)