Epson Ultra Premium isn't formerly Enhanced. Ultra Premium is the sheets and Enhanced is the rolls. I don't know the reason for the name change, but this was on Epson's marketing end for that part.
If the box doesn't have a proper label on it, it won't be the Epson version unless you typed it differently or it may be an pretty old batch.
Epson and Authorized Dealers should have the same inventory. We are an Authorized dealer and our inventory that our distributors hold comes directly from Epson. If a dealer sold a 3rd party version, they shouldn't have Epson labeled on the box (shouldn't but can be tricky if they wanted).
Try the Ultra Premium Presentation Paper Matte profile or the one just below it. The weight on the box should tell you which one it would be. Ultra (5 star) is 192gsm (10.4 mil) and 4 star is about 175gsm or lower.
Sitting on my desk at this moment is a 250 sheet 8.5x11 box labeled
Ultra Premium Presentation Paper Matte, and just above that name, in smaller print is
Formerly Enhanced Matte Paper. Except for the label that box looks exactly like the former box of
Epson Enhanced Matte Paper, including the colours, white, blue and green. If necessary I will scan the box and attach the scan. That box was purchased a few years ago at Vistek in Toronto. I agree that the later versions of the
Ultra Premium Presentation Paper Matte were boxed with a totally new look and did not have the text
Formerly Enhanced Matte Paper included. Since my only use for the
Ultra Premium Presentation Paper Matte is tests for printing on Canvas, I do not use the roll stock at all, so I have no knowledge of how that is boxed or labeled.
EDIT: I also have an older box of 11.7 x 16.5
Epson Enhanced Matte Paper that is also labeled in smaller print as
Formerly Archival Matte Paper. To me it means that until the past couple of years Epson has simply changed the name on the box but the paper was the same as previous versions.