BoyGeniusReport explains the reasoning behind the assumption, saying that the FCC ID number PB76110 is just a digit away from the original European Legend with an ID number of PB76100 and the design of the labeling matches the previous Legend as well.
AT&T could use a decent mid-high range phone for their line-up, but I can't think of any reason why Canada won't get it. For those of you unfamiliar with the structure of the HTC Legend, have a look at this quote from MobileCrunch for a good chuckle:
Sure, it’s not the most powerful piece of kit in HTC’s armory – but it’s made of friggin’ metal. You could give this phone to a bear for a few hours and have it come back mostly functioning. Can you imagine a world where bears have cell phones of their very own? That’s a world I’d want to live in.
Image from Engadget