I do get a 'realistic weather not supported by METAR" message though after I assume leaving my current tile. (...) What happens if you move outside of that tile on a long haul, for example? Under current settings in 2016.1.1 and with the new fix for the 2.0?
Will it stay with the same weather from KPHL to Dubai for example? Or will it change with the regional changes?
It would seem you're trying to misuse the weather engine.
You can drive AW either by supplying METAR or by letting it generate the weather itself by the offline engine. What you can not do is supply one METAR and then expect the offline engine to take over (loosely spoken, selecting a weather situation for the offline engine sets a lot more parameters, especially at higher altitude, than a METAR string contains).
So if you supply a METAR string and then switch the engine to 'realistic weather' (which is the instruction to the offline engine to generate large scale weather patterns), it's telling you that it won't do this.
In other words, you can't ask to be able to have control (by supplying a METAR string) and not control (by asking the offline engine to create weather).
All that has nothing to do with the bug and its fix which is about how the METAR string enters the system in the first place, because the weather systems are all agnostic to where it comes from, they just work from the parsed string.