Currently 2019.2 is planned for release the first week of November, so pretty much one month from today. Of course I can't guarantee anything, but that's the plan. 

From the changelog for 2019.2 I see:

-------------------------- FME 2019.2 b19734 20190729 -------------------------- 
Python: Added Python support for ArcGIS Pro 2.4. AFMEENGINE-60760] pTECHPUBS-6215] C146905 C146906 C147082

So it looks like that support is already in there, if you wanted to try the beta version.

This is now released - see https://www.safe.com/support/downloads/

The BETA we had been using previously was build 19778, and the production build is 19801