I seem to remember that one also when I signed up for the York Meet. Looking at the message, I thought back--Adobe updates usually occur automatically in the background, and then you get a notice on your system tray (the row of icons down next to the clock).
I don't recall ever seeing one specifically for Flash, just Acrobat...
...So I closed the tab, opened a new one and went back to the EDTCA site. Didn't see the pop-up again.
---PCJ