I don't think it's a high priority, it's just a thing that should've been done alongside introducing depth textures to plug the gap (note that the depth texture only supports 24-bit depths when going along with an interleaved stencil buffer, it covers
part of packed depth stencil, but not the part that allows to allocate a pure depth texture. depth24 doesn't cover stencil buffers, but it does offer a way to attach a pure depth only texture. Due to interleaving of depth/stencil on many implementations, using
a depth/stencil texture might have performance penalties vs. using a depth_component24).