System Information
Operating system: Windows 10
Graphics card: GTX 1060
Blender Version
Broken: 07f6be87a97e
When selecting multiple points in the weight paint mode, the Vertex Weights in the right menu (N), do not update unless you deselect and select a single one.
Here's a gif of it.
After thinking about it, I think again this isn't a bug but more of an unimplentmented feature. Maybe when you select all it's grouped up in 1 field (Bone, Bone2,....) and you could unfold it to access the rest of the bones?
Right, this is more of an missing feature than anything else. If you have a good idea on how this should work, post it over at https://blender.community/c/rightclickselect/