The upcoming conversion is teased via Bayonetta.
AllGamesDelta reports a rather interesting thing:
https://twitter.com/AllGamesDelta/status/856535047092006912
As you see, the PC version of Bayonetta got an update – a small one, including only one extra with the image from Vanquish. While there’s still no official statement from PlatinumGames, it’s a clear suggestion.
The company is busy nowadays. While Scalebound from PlatinumGames was cancelled, the studio released Nier: Automata and published Bayonetta on Steam. It wouldn’t surprise us if Vanquish for PC launched in the months to come.