I don’t know much, but I can tell you about bug-fixing based on my 32 years as a software dev.
Step 1 in bug-fixing is making it happen on the devs’ computer. Repeatedly. Over and over. Devs call this “reproducing the problem”. Devs can’t work on fixing a bug until they can reproduce it. Usually steps 2 on are quick, once reproducing happens.
Most of the many player posts about this gave NO clue about how it was done. They didn’t offer a way to fix it. Nobody “saw” anything, since what players saw was created by software. So how did the devs finally reproduce this? By tracking internet sites and power-levelers? I don’t know.
There was no proof. Your screen isn’t a camera. There are no real objects. Pixels are fake. You could only prove “my screen showed something that looks like teleporting”, which could easily be a bug in your screen software.
Nonsense. Solo queues for BGs have gotten many more posts than this bug. There may be 3 or 4 other topics that have had more complaints. Stop being over-dramatic, in your attempt to make Blizzard look bad.