Building a desktop game from scratch, what to keep in mind if planning to port to VR eventually?

I’ve just finished design concept for my game and I was torn between choosing whether to design it for desktop or for VR, so I asked myself why not both? I’m reading that in order for desktop games to have VR, developers need to create a whole new game from the ground up – essentially creating a whole new (but very similar) game but simply for VR. Is this notion wrong? I read another article that says it is but I’m unsure which is right. The article states that devs can simply port from desktop to VR if certain techniques or coding designs weren’t used. If true, what would those be? I’d keep those in mind as I designed my game for desktop and eventually ported it to VR if I could.