Twitter of shadow banning their accounts (which is funny, because I wouldn't be able to see their tweets if that were the case).
Don't automatically believe everything that that some outlets - including Twitter themselves - want you to believe regarding this as they try to clean it up. They are being intentionally obtuse and it makes me want to puke. I mean, Twitter playing dumb in their blog post about it was the height of "are you kidding me?" Basically, they are using terminology for a defense of what was going on. The folks on the bandwagon to dismiss this are akin to gun-advocates who say "you misused the term 'assault' weapons, therefore any discussion of gun safety is invalid".
Traditionally, a true "shadow ban" is as you describe. If someone were shadowbanned on a traditional forum like this, what would happen is that they would see their own posts, but no one else would.
What Twitter was doing was not that. About a month and a half ago, they implemented a "quality filter" that was automatically enabled. Interesting that the Twitter blog response about this just said "an error" was leading to some of this (the parts they admitted to), and didn't talk about this feature at all What it did was prevent certain people (mainly conservatives) from being picked up in algorithms and search results. There are various websites that you can use to test if your account was affected by this at the time, including politically neutral places.
No big deal, right - they weren't actually totally hidden? Well, that's not exactly a very genuine thing to say to anyone who actually uses the internet daily. If you are searching for a name, the only way to find it was by exactly typing it out all the way with no errors because auto-complete wouldn't work if they were subject to this "quality filter". So you could search for "Adam Sandle..." and it wouldn't come up, along with various other things they did to minimize these accounts.
So, there indeed was something really nefarious going on in trying to minimize certain voices on Twitter. Including those of some elected and those running for elected office. This isn't some crazy conspiracy, people have screenshots and evidence up the wazoo about it. It also shouldn't be a surprise, as this is similar to what Facebook got caught red-handed doing a few years ago.
I know many don't care about the actual facts here because it was "bad people we don't like anyway" but just like so many of these issues - what if Twitter changes hands and next time it happens to the far-left and not the far-right? Will people care then?