That’s exactly why Threads is incompatible with the Fediverse. Any huge server that is impossible to moderate for admins is detrimental to the network and failure to properly moderate is the number one reason we should be looking at to defederate from instances.
Automatic “spam” protection is the exact thing which co-opted e-mail. Big corps with the largest e-mail user base use algorithms that automatically assume the worst about any small e-mail server. If you spin up a small server you are assumed to be spam unless unless unless, which ended up with e-mail being centralized in the hands of Google, Microsoft, Yahoo and Apple, despite being theoretically decentralized too.
Is that what we want for the Fediverse? 4 or 5 huge instances automatically defederating from all small instances unless they fit some criteria defined by the big corps, which they can change anytime?