There is a lot of FUD it seems in the story.
iX recently talked about their plans for TrueNAS CORE.
TLDR: CORE is not going anywhere, for at least a handful of years.
https://www.truenas.com/blog/truenas-core-13-3-plans/
Below, a comment from Kris Moore SVP of Engineering at iX:
"VM’s transfer over perfectly to KVM on TrueNAS SCALE. Its only Jails and Plugins that need to be re-created, but all the data persists just fine."
Thanks -- that's my story.