That's shocking, sinevibes is a legit developer in the music/audio space. They made the FX for dreadbox's Typhon synth and several popular FX plugins for Korg logue synths. I'm subscribed to their newsletter and have never received spam. All their youtube channel had were demos of their products, as far as I recall. Like "here's how the dry synth sounds, here's how it sounds with reverb", can't even imagine how an algorithm thought it runs afoul of a spam or scam policy. Probably a mistake, hope it's fixed.