I have no clue of when - I’m not affiliated with VCV in any way.
But having read this I have no doubt we will get VCV Prototype in Rack2 eventually. It was a “selling point” of Rack 2, that VCV would see to that all v1.1.6 opensource plugins were ported (if the porting was straight forward). When? when!
The latest commit to VCV prototype was 1 month ago - please be patient.