I support a change in general, though I don't like the approach. I'm disappointed that Plarium spent so much time on building this new content, then going through all the UAT processes, only to find out "oh, we forgot about the Paragon cheese". It's just yet another instance of shoddy development standards, and I really wish Plarium held themselves to a higher standard.
The problem I have with doing a blanket "ignore unkillable" change is that it then also removes any build or tunes that incorporate other unkillable champions.
Instead, I would have preferred a solution such as incorporating some sort of mechanic whereby after XX conditions are met, then the Iron Twins ignore unkillable/block damage. This could be XX rounds like CB, or XX stacks of a debuff/buff like Griffin. There's even an "Iron Brand" debuff mechanic to this boss that could be utilized for this very purpose, as it increases in stacks as the fight goes on
This would allow players to still attempt builds and tunes with unkillable, but would essentially result in a single paragon not doing enough damage to kill the boss fast enough before the above criteria is met
and why unkillable TEAM is acceptable, but not the paragon? if paragon is a cheat, then unkillable team is a cheat too - in both cases requirements for stats are not met lol. paragon is easier? ofc, but its also much longer run.
in both cases original requirements are not met.