Don't forget the fault that lies on SE. Who the hell leaves one shot mechanics in two tier old content and still requires a clear? The echo buff is not the only "nerf" those encounters need. IMO, one shots should be taken out of old content completely, but if they want to leave them in, then only the prievious tier (6-9) should keep it. Two tiers back (1-5) should definitely not have them. It's dead content to anyone who cleared when it was current.

Inb4 "Lol, I don't want those baddies in my raids and I had to do it pre-nerf." If they weren't in your groups while the last tier was current, they won't be in this tier, either. Leave them alone and let them have old content. It doesn't hurt anyone's prestige who cleared it when it was current.

Also, inb4 "no, I want my content to be hard whenever I get to it!" Then clear it while it's current. I get it, time constraints suck, but don't selfishly cry to bar everyone else for months just because of your unfortunate game time.