Hey All
I just had this happen o me , and I see there are other posts about it already. Just want to add to that voice and say this a extremely frustrating action. as it takes one key press to move a project into a certain state. ( show just that layer ) but if I had 100’s of layers all with varying visibility… then that scene setup is now lost. There is no way to revert to the previous visibility set up, other than the undo history , which is rather a tacky solution and also very destructive if you perform a few other actions after the num key command. Because then you have to undo all those actions to get to the undo of the num key… horrible stuff.
Also the num key controlling collections isolated visibility is kind of making the layer system be base 10 again like the previous blender… what if I have 50 collections? there is no num key 50 now is there. This proves it is a silly short cut because it cannot function on any collection , only the first 10 , this smells of blender 2.79.
The biggest joke is that it happened by mistake, I actually thought I was still in edit mode and wanted to switch to edge selection. This is just a horrible idea. Laughable when you have 3 or 4 collections… tear jerking when you have hundreds.