DLC can mean a lot of things, from horse armor to something like Blood and Wine
If real, this is nothing more than something like the Netflix Witcher tie-in DLC with one new mission and armor. Something that CDPR can make in a month to tie in Witcher 3 with 4
Anyone expecting something like Blood and Wine or Heart of Stone are delusional
I think they want to turn Ciri into a full-fledged Witcher through the Trial of the Grasses before The Witcher 4, to justify giving her Witcher abilities like potions, etc.