Man, now I’m quite pi**ed, I have to say that. I really thought they’d changed something significantly. However, the “only” thing they did was to inject METAR into the game at and around airports. Period.
If anybody here wants to verify this: Spawn at a place like KTEX (a high-elevation airport) and take off. On the ground and at less than 5 miles around the airport, you’ll get METAR conditions. However, as soon as you go further, the OAT will increase (and maybe the pressure will decrease as well, didn’t check it yet) to the completely unrealistic values we are used to until now.
To me that proves that they’re using METAR at US airports now, the weather extrapolation or their corrections are still incorrect, though.