The rumors about The Witcher 3: Wild Hunt will be ported to Nintendo Switch still continue to appear, firstly noticed in December 2018 they’ve been resurrected due to leaks and an international retailer updating their web store with pages for the game. We can strongly assume that Geralt of Rivia will make his appear to Nintendo.
There also another strike, as The Witcher 3: Game Of The Year Edition for Nintendo Switch, has been found by the ResetEra user Jim_Cacher, and according to him, the release of The Witcher 3 on Nintendo will happen this September.
“[Breaking! Witcher 3 GOTY edition is coming to Switch in September.] According to a reliable source from distributor, Witcher 3 GOTY edition is coming to Switch in September. Chinese localization exclusive to Asia version.”