This chapter is NOT a retcon of Endeavor's past actions or behaviour. This chapter does NOT ruin Dabi's reveal in any way. Anything you feel was changed was just your headcanon of the story, nothing ever put on paper.

Endeavor still physically abused Shoto, that has not changed. Endeavor still neglected Natsuo and Fuyumi, that has not changed. Endeavor STILL had eugenics experiments. What has changed is we know what happened to Touya, and how Endeavor acted before his descent into madness.

What we saw was Endeavor's selfish ambition grow stronger and stronger as Touya injured himself and All Might kept getting strong and stronger. It all still leads to the same end point, of Enji abusing all of his children and him being an asshole.

Dabi isn't just some 'spoiled brat'. Physical abuse isn't the only form of abuse. He was given a dream and dumped after Enji's selfish desire led him to having more children. He was built up, dropped, then neglected.

He witnessed Fuyumi, and Natsuo also being neglected. He witnessed Shoto being physically abused and separated from the rest of the family. He still hates Endeavor for the things he did to his children, and he still, just like Stain, wants to punish the epitome of a false hero.

Everything we have seen remains consistent with our initial impressions of these characters, all that has changed is we got a deeper look into how we got to today. Endeavor isn't a black & white evil character, and Dabi wasn't just 'born crazy'.

I by no means endorse the actions of either of these characters, they are both shit people. I just have a problem with people trying to say that Hori is attempting to negatively retcon the actions of Endeavor, when all we got was new information and recontextualization.