This is just a Beta, but HARMAN has done a lot in this release and seems to be laying the groundwork for even more:
Some changes to AS3 include:
AIR-6085: Debug SWF files to include their location for debugger monitoring
Source code paths are already mentioned in debug SWF files but with the path to the generated SWF file we are planning to add monitoring of these files in case of changes, that could then be reloaded automatically into an ADL instance... (work in progress).
AIR-5678: AS3 to support null-conditional operators
You can now write val = obj?.prop; as a shorthand for val = (obj == null) ? null : obj.prop;
AIR-5761: AS3 to support nullish coalescing
AIR-5676: AS3 to support verbatim strings
You can now define a string with an @ symbol at the start and then you don't need to escape backslashes.. eg. @"c:\users\test.txt"
There's also native classes for timezones, getting notch info, android config for adding AIR to app id etc. Really recommend reading the release notes.
Oh, and also a side mention about a new SDK manager to handle only downloading the bits you need when parts of the SDK update 🙂