About the need of global Properties

Recently, there was a discussion in the normal community forum, if global Properties are still needed.
I want to give a real example from my test of AnyTwo:

All my Objects get always an own date Property, so that I can sort all Objects for this date, no matter where they are.
The mentioned date is in many cases identical with the Creation date, but it also often differs from it).

Now the thing:
yesterday, I've created a Page and gave it the yesterday's date.

Today, I've added a video into it. Because I have also a Collection "Videos that I've seen", I added the header Tab of this specific Collection to the Page.

The trouble: in this newly added header Tab, is also a date Property, but here it is still empty, because the date Property is not global.
But I want that the whole Page has one specific date, no matter what header Tabs are used.
Of course, I could manually set the same date a second time. But this can't be the solution on the long run.

In my management philosophy, a date is always related to a Page as a whole. No matter of later edits in that Page and no matter of the chosen connections to Collections, etc.

Actually, I can't see a way to do it without unnecessary redundancy of manual steps.