Did you try to contact directly Alfred, Peter or Brian? :)
https://bugs.debian.org/816277
I appreciate that most of the time reporting directly is the right thing to do, but often there is a good relationship between packager and developer and things flow well in both directions.
I guess I should make sure I chase old reports and reroute if they seem to be orphaned/ignored/overlooked.
Sometimes I go through things, but its easy to think you've done your part if you submit a bug report, a reproducer, and even a patch.
I'd expect that once a patch is there and it is consistent it would be applied, whereas just reporting what a fuzzer finds is not too helpful.
By the way, we've all seen the XKCD about competing standards before.
Maybe try sending an email? I agree that reporting to the Debian packager often works, but in this case it's possible they just have too many things to triage appropriately.
Edit: Too late I see it was already reported before the release and apparently wasn't regarded as significant:
http://lists.gnu.org/archive/html/bug-gawk/2019-04/msg00015....
I guess that means no fix.