It seems Valve has not forgotten Team Fortress 2 exists and a fresh update is out now, which pulls in some new security measures and the Summer 2021 Cosmetic Case.
TF2 has struggled for a long time now against bots. They've been going wild, ruining games, putting vulgar things in text and voice chat, changing their names to terrible things and plenty more. At times Valve has slowed them down but it's never long before the bots are updated to overcome the new measures.
In the June 22 update Valve noted "Numerous security and stability improvements" were implemented, along with many other smaller updates like having a cooldown before a vote can be created once joining a match, a configuration variable has been added to control players changing their name during a match with matchmaking servers having that turned off by default, the disconnect reason message when players leave was also removed (bots no longer get the last word when kicked) plus some other miscellaneous changes. The Summer 2021 Comestic Case also brings 18 new community-contributed items and 6 new community-created Unusual level effects.
Going by the reports (like this), it seems that initially the update crashed the tool most cheater bots used however, looking around, the bot developers may have now solved that already. Even so, the other measures like name changing and bots getting the last word which has also been a problem is nice to see getting some work done. Perhaps this is the start of more anti-bot features to come.