Ok. Your comment brought nothing very interesting in my humble opinion. What's your opinion on the move? What particularly makes sense to move Trueness to Linux?
The original ixSystems explanation was what made the most sense: their engineers spent more time developing freebsd itself than trunas. Unlike on linux, where the ratio was different. So it's not a surprise, that they prefer the better maintained platform.
ZFS is maturing on Linux and the codebase and general focus is on Linux today.
Hardware compatibility and mindshare are also big factors.
It seems like a subset of the TrueNAS community reveled in the fact that Core was FreeBSD-based. Maybe just a bit contrarian.
I've had meh experiences supporting, repairing and transitioning installations away from ixSystems. I wouldn't advocate their offerings in the first place, but it does seem like you have unrealistic expectations from ixSystems.