I can access the website (smartmixer.io) without any difficulty, all pages seem to be loading in quick time. If what they said it true about the DDoS they certainly should have made an announcement on their website that they were under DDoS attack and were in the process of getting things back to normal as a courtesy to users.

The failure to do that along with the locking of their threads and it coinciding with the end of their signature campaign here - makes it look very suspicious indeed. Add to that the Telegram message then all becomes clear, sadly another exit-scam going on.