I hope they add the ability to animate the visibility of collections but until then I found a way that works ok.
As blender lack the ability to add keyframes to all selected items for visibility or add all selected items to a keying set, you need to make a script.
I did a quick script that add the selected objects to a keying set for visibility, now you can easily keyframe the visibility of many objects without even have them selected. Just select the keyingset and add keyframes.
