Well…kinda sorta…
Saw over at Neowin that some people have 1903 showing up via “check for update”. Not for me. All I had was May 21, 2019—KB4497934 (OS Build OS 17763.529). 1903 is available for download:
https://www.microsoft.com/en-us/software-download/windows10
I’ll wait and see if it shows up tomorrow.
Win10 1903 Available Now
Thanks Eric! Maybe they got this Version right – at least with the option ‘not’ to install feature upgrades.