@jschievink to be fair to @kornel here:
The linked fix PR for the issue was originally opened May 20th, and beta nominated and (master) landed September 18th. It was declined for backport on September 24th, and @kornel asked for the beta backport decision to be reconsidered on October 1st. After little/no more discussion on the issue, @kornel brought up the issue here to bring more attention to it (which appears to have prompted @Mark_Simulacrum to formally renominate the patch and provisionally accept it for backport).
Or in other words, the impact was known. The fix was considered for beta backport (because it's known as fixing a regression) but was (wrongly?) rejected temporarily (due to patch size and a slight miscommunication about the scope of the issue, it seems?), and this post was to bring more attention back to the need for a backport.
(It's also worth noting that the issue was introduced into 1.46 by a backport as well.)
(Note: some dates may be off by one due to fencepost errors where GitHub is just giving "N days ago" rather than saying the actual date.)