I can't believe a 'privacy-respecting open-source' tool is spamming this way in an unsolicited manner.
At least if a user would have subscribed like "hey please notify me if I post a link to YT so that I can fix my post?", it would make sense.
Currently, you are just being impolite and doing a disservice to your tool/product.
I'll report the bot to my instance's admin and will block it.