Pure speculation, but here's a possible explanation. .win entirely is a suspicious TLD.

As such i wouldn't be surprised if Malware Bytes just pops up the warning for the entire TLD.

I would imagine they manually whitelist TDW, here and other legit sites as they come across them.

The new site's only just became a thing and it's probably just not been updated yet.

It's certainly worth raising an eyebrow over and checking out further but... In and of itself this is potentially resolvable with an email to Malware Bytes.