Hi Paolo,
I've done some simple tests in 11.1, and according to them EA treats a request to open the same shortcut that opened the current session as a close-and-open: it requests save confirmation in open diagrams, closes the diagrams, opens the default diagram and resets the project browser to that diagram. The behavior is the same whether you use the Recent section of the Start Page or the File menu.
If you use File -- Open / Ctrl-O / the Open toolbar icon, the save confirmation dialog is brought up before the Browse dialog. Other than that, same behavior.
Using a shortcut to the same repository but with a different default diagram again yields the same result.
File -- Reload Project is different. It requests save confirmations as necessary, then reopens the set of diagrams that was open and collapses the project browser. The reload process is noticeably quicker than reopening a shortcut.
From this, I would conclude that
1) EA does not keep track of which shortcut was used to open the current session, and
2) Opening a shortcut implies closing the current session first.
Meaning that
3) The cake has been eaten.
So in answer to your question, it appears that EA does not as such perform any checks like the one you describe.
On the other hand, the end result is that you do get back the (set of?) diagrams from the shortcut, it's just that the project is closed in between so it takes a little longer (or a lot longer if you're not using lazy load but who wouldn't in this day and age) and your credentials are presumably rechecked.
In MS Office, the behavior is different: requesting the current file from the Recent list is simply ignored: there's no save confirmation and as far as I can ascertain no reload of the file. But files are different from sessions.
Considering that shortcuts are just that, shortcuts, I think the current behavior is OK. If they were called stored sessions it'd be a different story, but a shortcut is just a way to get into the repository and I don't expect EA to remember the shortcut once the session's been opened.
And you owe me 2c.

/Uffe