Well that script was ran on enough other computers, so the magic algorithm decided if everyone else ran it, it must be fine.

What language was it written in? I read that Microsoft Defender likes to flag the baked-in runtime of some languages as malware because they commonly shows up in actual nalware.

The script was from a verified source.

You mean it was flagged as malware? You must have written something that was deemed very suspicious. Or it is one of the few false positives.

Also, that batch script would be flagged the moment it ran.

Sounds like a step towards forcing developers to pay Microsoft to let them run their software on Windows.