Anivia adjustments on PBE require compensatory buffs
Nerfing the R-E/E-R combo without giving Anivia any form of compensatory buffs is pretty much putting her in the garbage can. She already has a bad pre-six laning phase against a competent player. Even after hitting level 6, it's not like she can completely screw the other enemy laner. She has massive mana costs compared to other mages. The nerfs don't make much difference to her team fighting, but waiting around for a few seconds just to do the full 200% damage against another laner is ridiculous and will never happen against someone who isn't playing on a wheelchair. If she does less damage with her combo at the very least, lower the mana cost or give some sort of compensatory buff so she doesn't completely get dumpstered in lane even after hitting six.
These changes are going to affect her post-six gameplay dramatically. There is absolutely no way someone is going to just stand there in her ulti until it grows to full size for her to do maximum DPS. Nerfing her combo without giving her any compensation will make it so that she won't even be able to play aggressively. Inb4 "hurdur e-r is easy to land. this makes anivia require more skill to play". No it doesn't. Anyone that thinks that is actually in a wheelchair. It changes absolutely nothing about her teamfight because a well positioned ult will be in full size and she will pretty much do the same damage. Her laning phase is going to be even more shocking though because she is going to OOM before being able to kill or properly zone her opponents out of lane. Before 6 she can't afford to use her abilities as often as other mages to farm waves. In fact, she has absolutely no dps against a good player if she uses a single ability.
Edit; Yeah I can't be bothered trying to reason anymore. In fact, why am I even bothering to reason to Bronze-Silver players that are telling me Anivia's Q is hard to dodge. Zzzz...