I think however this "seperate issue" is very relevant, because the employees (which potentially pushed for his removal) are now the ones with "Justice" on their lips.
When you want justice, you can't turn a blind eye on injustice.
And due to Flynn being alleged of sexual harassment, it certainly has connections to the current situation at Blizzard.
If the employees essentially turn a blind eye towards this now, it will very much tarnish their movement.
You can't expect people to take your "Everyone has to recycle for the sake of the enviroment!" movement serious, when you also drive an SUV / Pickup Truck that needs how many gallons / liters of gas.
I think it hardly matters either way.
If they removed him because of cancel culture, they are freaking hypocrites considering what is now going on.
If they removed him to protect their brand (because money), then the employees should also stand up for him because he's been subject to disrimination on Blizzards end.
I'm not well versed in american law, but as far as i know, you can also fire employees unless the employee can showcase that said firing based on rather questionable reasons (gender, religion, political view, etc.).
Disregarding that, i don't expect the employees to change the law but i expect that when they demand justice, that they actually mean it and the just thing is to at the very least, restore Flynn voicelines.