Either date is fine, the American Orthodox Church follows the Old Calendar for 99% of events but accepts the revised Christmas date because it is entirely plausible and basically in the same time frame (about 6 months after the birth of John the Baptist), and it is easier than trying to fight Christmas tradition in the West. Trying to fight something like a date could be a pointless obstacle for those seeking to convert.
Conversely, for something like Pascha, the date is always after Passover, as it is explicitly stated in the Bible, so there's simply no room to compromise on that. Other dates and feast days aren't major cultural events, so there's no need to consider any changes for them either. It's basically just Christmas, which all of school and work holidays center around in Europe and America, so in the name of economia the 25th is observed as to not place a pointless obstacle for the faithful. Jan 7th is already when people are working again, with children at school, or returned to college. The Bishops of America decided on this awhile ago, and I believe all of Greece has accepted this compromise as well.