No, it doesn't. Initial has to be done in EU airspace but revalidation/renewal can be done anywhere.
This is the same info I got from the CAA when I called them.
And I had the same problem finding someone on the West coast to do a revalidation. Still haven't found anyone. I think I read somewhere that the CAA has not appointed people who can do revalidations outside the EU; although who knows why they are so hard to find.
I decided to let my IR lapse and I'll just revalidate a few months later when I return to the EU.
I did find a few places that will do a SEP revalidation though; that is the one you don't want to let lapse.