I don't know what to tell you, except that people sometimes say things which aren't accurate when they believe it will advance their personal interests.

I can't disagree with that. :-)

So Bryan Cantrill (CTO) and all the former Sun eng. will abandon SmartOS @ Joyent?

I doubt that Joyent/Samsung will abandon their work on-top of Illumos. They contribute work upstream to Illumos.

They continue to port code to Illumos (i.e. KVM, continued work on Pluribus port of bhyve, etc.).

SmartOS is what their data centre orchestration solution gets built on-top of.

You can see their changelog for SmartOS they are quite active: https://us-east.manta.joyent.com/Joyent_Dev/public/SmartOS/s...

Development of SmartOS and Triton Datacentre occur under their joyent organisation on GitHub.

The rumor is that the decision was made above that level.

Any links/sources you could point towards, even unofficial rumors?

No, just word of mouth.