Ah yes, that's a very interesting service. I call it a tramp steamer, AA425 is actually US425, which starts life in Portland Oregon, comes down early in the morning to Phoenix, continues on to Kennedy, and then pops down to Charlotte. I've done bits of it, but one day I'ld like to do all of it from PDX to CLT on the same aircraft, which is trickier than it sounds since they generally swap equipment over en route. For PHX to JFK it's generally an Airbus 321 which is a good First option at least.

Now at PHX they only allow one hour for the turnaround, but they allow 90 minutes at JFK, which indicates the error range. Having said that, in normal weather, if you leave PHX on time you will get into JFK about 15 minutes early, however usually to the satellite building, whereas AB generally goes from the main building. US425 has a 77% chance of being on time, which is quite poor for US.

Do-able? Just about. But it's not for the fretful or unfit traveller. It would be a minor miracle if your bags made it too. So make sure you take any chargers (etc) with you since you may be separated from the bags for a few days.

And think through the implications of missing that service. Three days a week there is a later AB flight to Tegel, leaving at 21:55, but indeed the more usual result is being sent via LHR or LCY on BA. However BA's JFK services are often well filled in premium cabins so there is a downgrade risk there - which you won't know until you get to T7 if AA don't issue a boarding pass with a seat number on it. AA are known to re-route on other airlines if the delay was mechanical (not for weather) so you may be able to request to keep business class by flying on Lufthansa (unfortunately that's the 747-400 series, not 800); or Air France's 777 service.