The account tagged with "trends blacklist" and "search blacklist" was also tagged with "compromised", which suggests that the account was known to be hacked by

The account tagged with "trends blacklist" and "search blacklist" was also tagged with "compromised", which suggests that the account was known to be hacked by a malicious actor so it was set to not show up in discovery flows to stop attackers from exploiting it for visibility. Does confirm past claims that they shadowban accounts (which does hide them from search, among other things) at the very least, even if the exact criteria are unknown.