I don't think we'll see Sims 4 on VR for the simple reason there isn't a lot of people with VR right now. I had VR when I had the Note 7 before it's firey recall. I didn't want to buy another VR for my Note 8. With phones you have to continually upgrade to another VR thingie because of their size.
Stand alone VR probably wouldn't be able to handle a TS4 game and VR on Sony is way too expensive right now. Same on the PC. If the Sims team was to make a VR Sims game I'd hope they'd go with Stand Alone VR were you don't need a phone to use the VR Thingie. Stand alone VR is cheaper to buy right now and you don't have to worry when you upgrade your phone and it's larger it won't fit into a phone VR.