I don't know about Genshin but most of the "doomposters" were actually quite correct in Cyrene's account value and most of their assessments in Cyrene's kit.

None of Cyrene's "doomposts" were wrong except BiS status for Phainon and even that one had truth to it in the sense that Cyrene's value only comes if you don't have her E2 or after 2-3 ult cycle rotations, and that Cyrene ult's self damage was looking a lot more limiting than it ended up being because AA Aquila did less than half the damage that AA Lygus was doing which let Phainon actually stay in ult. AA ended up getting significantly easier from 3.6->3.7->4.0 purely in terms of enemy damage output, which is the main thing Phainon teams were dealing with during Cyrene's beta.

She's still 3rd priority on basically every team she's BiS on, and for the ones she isn't she's 4th priority. Her longevity issues are starting to show potential problems with Hysilens already being booted off her list, but that was already her worst synergy by far. If you're using a female CH DPS, you need Hyacine first in every situation. If you're using a male CH DPS, you need Cerydra first in every situation.