While I think the dwarves would jump at the opportunity to get rid of the casteless I don't think southern thedas would do that.

If the alienages and cities like Kirkwall are indication the rich just leave the poor to fester and die. Occasionally going in to get their rocks off in the most cruel ways possible.

Giving the poor and undesirables weapons and making them organized is a very short sighted move because unlike golems you can't just magically control them and you risk putting your own head on the chopping block if the truth about rhe joining and how you enabled it gets out.

Also consider that in the centuries since the 1st blight no country has tried to take over the wardens and that its always the wardens who try to seize power not the other way around.

I really think they'd just say fuck it kill em all they're a bunch of blood mages and have tried to stage coups before and they are clearly lying about their importance.

Throw in the blights happening every couple hundred years and darkspawn not being a serious surface issue and it makes the most sense that outside of Orzammar and maybe tevinter that southern thedas would justify destroying the order instead of keeping it around for their own self interest.