Yes, Version 1909 is out – actually it’s been available since October 2019 except it didn’t show up for the general public. The below Microsoft Tech Community blog explains why:
In short, anyone running build 18362.418 or later (regular October 2019 cumulative update) has been using Version 1909 without knowing it; this is accomplished by storing Version 1909 code, which an enablement package (KB4517245) will find and activate it once Version 1909 is offered to you officially via Windows Update (not yet for most of you). This also opens up a possibility to “uninstall” Version 1909 by simply uninstalling this enablement package, reverting you to Version 1903.
As pointed out by Windows Central and other sites, this “backporting” is necessary because of changes to Windows development schedule to align with Microsoft Azure. The next ‘real” feature update is Version 20H1, made available to more Insiders yesterday when build 19013 was sent to slow ring Insiders, with no firm date as to when it’ll be finalized (December at the earliest).
In summary, you don’t have to be too anxious about Version 1909 installation going wrong, but take usual precautions. You still need to take more precautions when moving from anything below 1903 to 1909 (say, from 1809 to 1909), as it’ll be just like any feature update installation – 1903+1909.