GLTF2 is a new format from the Khronos Group (the people behind technologies like Collada, OpenGL, etc). Unlike FBX, the GLTF2 format is designed fully around PBR / phyically based materials.
There is a working Blender exporter for this format already, that works well with Cycles. With FBX right now, we can not just simply export a Cycles material and automatically have it work in Sansar. We are forced to use Blender Render or just simply assign textures manually in the material editor.
But if Sansar adds GLTF2 support, we could have a fully Cycles-only workflow without ever having to touch Blender Render (which by the way, is due to be replaced in future Blender updates).
Here is the documentation for the GLTF2 Blender exporter. It shows you how easy it is to use.
I think it would be valuable for Linden Lab to add support for this format to Sansar! Many of the issues Blender users may be having right now with textures not showing up correctly would be resolved by switching to this format. GLTF2 supports embedded textures, without the issues that FBX has with that.