> Has there ever been any actual indication of twitter shadow bans being a real thing
Please stop living in this bubble. There have been plenty of reports of Twitter shadow banning speech it doesn't like. It has even suspended accounts multiple times only to reinstate them by saying it was an "algorithm error" or it being "wrongly flagged". In India we regularly see Twitter suspending accounts that have not violated any Indian law.
All because it doesn't align with the left-leaning ideology of Twitter. Even trends are boosted to favor left-leaning news portals over right-leaning news portals (which is visible in the trends section).
An example: https://www.freepressjournal.in/viral/bringbacktrueindology-...
^ This account specifically was suspended a total of 3 times. Ultimately the anonymous account owner decided to come out in the open and open a Twitter account in his real name. He got banned again very recently. In all those instances, there was not even one tweet of his that "crossed the line" when it came to anything illegal. Be it speech, instigation of violence or even a curse word. Nothing at all. The suspension was purely ideological.