huh? What's tumblr got to do with this? Is this about Automattic adding the ability to connect up Tumblr accounts to the fediverse? Because you do know that isn't the same as the Threads situation right?

It's very probably going to function like how Wordpress and ActivityPub already functions - as a way to let people look at and interact with your blog from a Mastodon or other instance. And if Wordpress is anything to go by it'll also probably be limited to self hosted/paid accounts rather than something that everyone can have so the bot/spam/ghost account worry is kinda moot

There have already been instances found that had thousands of bot accounts, they've been defederated but clearly people are gearing up