Windows 10 1903 was released on 4/18/2019. I got the ISO, attached it to a newly created VM and attempted to boot from it. I get the prompt 'Press any key to boot from CD or DVD' and after I hit a key I get the windows logo displayed and then nothing. It just sits there, I have let the VM idle for a few hours just to ensure its not actually thinking away. The vCPU usage is running however - looks like its taking an entire core but actually nothing happens.
I was able to get the ISO to boot, install, and run the OS on VMware Workstation 15, and Microsoft Hyper-V but not on vSphere / ESXi host.
Here is some additional info that may or may not be useful
Workstation build: 15.0.4 build-12990004
ESXi Build: VMware ESXi, 6.7.0, 13006603
vCenter Version: 6.7.0.30000
vSphere Client version: 6.7.0.30000
Attached the VM log file