User blog comment:Spiritfan08/Just Dance 2020 - BGS Reveals (Unofficial)/@comment-26573805-20190826200341

Teasers and songdescs can be faked by anyone. And the post in the "Telephone teaser" video you attached to this page very clearly says it's for Gamescom, and official JD teasers never use a #Teaser hashtag.

The possibility of Thunderclouds in Just Dance 2020 is uncertain, however it is very guessable based on official artwork for the game in the fankit which also contained a hint that Con Altura was in the game.