Yep, pretty much.
More specifically, it's translucent materials working with reflection probes. Slightly more generally, this means forward rendered materials working with reflection probes. Ideally, we make the forward materials utilize the exact same math that our PBR deferred materials do, for consistency, but the main focus is probes, because normally speaking, the only forward rendering materials used in deferred are translucent materials, like glass.
When I get the math shored up, the glass'll reflect the nearest probes' reflections - parallax corrected just like on the deferred PBR surfaces - and it'll look really nice. Following similar math to the regular PBR materials, metalness infers towards how reflective it is vs how much the diffuse material contributes.
Pleasingly, also takes the normals into account, so doing warped glass, or the natural distortion of plate glass is super easy to do as well and should look great in the end.