Not sure if bug or feature request, feel free to move if posted in wrong section.
Related: also cannot cancel an invite from the Alliance admin’s site. I suspect that may be a bug.
On top of this, if you destroy an alliance, then create a new one with the same name, you’ll maintain the invite list.
I’ll need to look into this, alliances were in a pretty early state when this stuff was implemented originally, I’ll look into doing some cleanup.