I just can't see that cost of having a free Linux version (on top having a paid Linux version) is big?
There's no bait and switch. It's just people expecting things for free, as always, when this was never an open source project.
In Vivado, it's the same release for the free and expensive builds on both Linux and Windows. It's just a question of the installed license file/license limits.
> such as the Linux builds require proprietary 3rd party code with royalties, and they chose not to eat that cost.
This seems unlikely for a multitude of reasons.
And for those who forget RHEL for instance has to pay salaries to back port fixes and such and the same logic applies here.