There's a lot of hate going around here about retconning, but we've got to remember that back in the day saying stuff like: "By the Force! I thought a lightsaber could cut through anything. The walls are barely scratched. The only thing that can resist a lightsaber is…Mandalorian iron!" Now we just gotta take that stuff with a pinch of salt
I also understand there is a lot of controversy surrounding the 'New Mandalorians' - but I think the hate is unnecessary, eventually the Mandalorians are going to get tired waging war against the Jedi and constantly getting put down and eventually try and form some sort of stability. And personally I think the idea of a traditional war like culture abandoning its ways and becoming pacifist, threatened by terroist groups such as Death Watch who wan't to see the return of their old ideals, is exciting, unique and interesting. Another Mandalorian cult causing trouble would be, in the words of Darth Zash "dull dull dull dull dull".