To be honest, I am sure it would be a lot easier to just fix the bug, or at least acknowledge it than reply to these comment threads. To the complainers: I see that it has become a little bit vexing to the moderators, so maybe just calm down about the issue for now.
I hav had the same issue for a very long time, at least from 1.8. I'm glad someone else finally noticed.
I believe this applies to more than piglins in bastions, as far as I can see it applies to any hostile mob, the only way I've seen to get them to re-visualize is by either quitting and reentering the game, or by shooting them with a crossbow held in the off hand.