Difficulty of normal content.

[JowyAtreides]

I don't think this was any more difficult than we've had in previous expansions' raids upon release to be honest.

Use and abuse of non standard telegraphs.

I'd say the vast majority of normal raids, upon release, has mechanics only really seen in that raid, this is no different.

Nasty mechanic overlaps, stuff you would see on extreme and harder fights.

Mechanics are shown one at a time and overlap, this is normal.
Extreme and harder fights don't give you this luxury and throw you right in with overlapping or even completely different mechanics

-Mechs resolving too quickly for the mental capacity they demand to process.
-One too many "catch this!" mech (mechs that have you running around like headless chicken evading seemingly random patterns).

Addressing both of these at once because the mental capacity of players will adapt once they learn the fights, if you want it easy on day 1, it will become face-rollable after 7 attempts, this is bad design.

I genuinely think people just forget what it's like to get something new to do, because it's been the best part of a year since we've had any content to speak of.

TLDR

Run it, get better gear, watch the mechanics, adapt, overcome and proceed.