It is probably due to the fact that our domain is "similar" to "reddit", & the domain "reddthat.com" is less than 30 days old. It looks like malwarebytes also crowd sources their issues. So someone probably reported it to malware bytes as "bad". Probably one of the bot actors.
If you can click "don't warn me again" it should eventually feed back to MB.
To get it removed, looks like I have to signup and submit a request for removal on their forums... What browser is this happening on as well?