Lmao no, what you're seeing is legit raids being shared through RNG abuse. I think someone mentioned it in the past two pages. Basically, they exploit the daily raid changes and keep checking a den with a wishing star, until they get their desired shiny. Then, they share the raid with friends or other communities through discord, Reddit, or twitch.
I'm currently following a few discord communities to be able to get certain GMax Shinies I want. So far I've gotten Charizard and Hatterene, but that damn Gengar keeps eluding me. I've tried so many times but it won't stay in the damn ball. 😤
This is amazing. Probably the easiest way to get legit shinies ever. I'm never going to stop playing this damn game.