Normal difficulty should be accessible without mandating optimization at cost of story.
This is something I can agree with. But it would be enough in that case to simply reduce AC without overhauling the entire DnD 5e ruleset.
I'm fully expecting a hardcore d&d setting to be different from default difficulty where ACs might be lowered. But I agree the HP shouldn't be raised. Increase the number of goblins, not HP. Have they said anything about difficulty settings?
It would be nice to hear confirmation that there will be a hardcore setting with actual rules.