Borderlands 3 will come to additional digital PC storefronts in April 2020

[Windows Central]

Best answer: We don't know for sure, but there's a strong possibility that Borderlands 3 will come to Steam after its 6-month exclusivity period on the Epic Games Store.
Vast alien treasures: Borderlands 3 ($60 at Amazon)

Full story from the WindowsCentral blog...