It's on reddit and twitch that's why it's not appearing yet on search engines but later, for sure a lot of esports article will come out for it.

--> https://www.reddit.com/r/DotA2/comments/s8fyoy/sunsfans_news_about_winter_majors/

This also covers the TI qualifiers wild card and it's said that it's going to be on LAN. Read the details that tell all of it on that link, seems legit but let's all wait for official announcement from Valve.