Regarding hardware instructions, Easytrieve currently generates ARCH(0) code, so there is no use of instructions in new Z series. This being said, the Easytrieve Development Team has started a modernization project (very early stages, not committed yet) of compiler modernization that would allow Easytrieve to generate code on higher arch levels, allowing the benefit from their investment into HW and get better performance.
When it comes the drop date of Compatibility mode, as of January 2023, there are no dates at this time to be announced. It all comes down to evaluating the needs of our customers' environments and the releases we support, making sure the underlying tech stack is constantly maintained and modernized, especially against security vulnerabilities.
Being on the true 11.6 compiler (newfunc) is future proof and highly recommended as all of the existing development is happening on top of Newfunc! The above means that if Easytrieve Developments proceeds with the modernization, it will be on top of newfunc mode. Currently all Easytrieve versions: 6.4, 11.6C (NEWFUNC=N), 11.6 (NEWFUNC=Y), generate ARCH(0) code, which is executable on all IBM Z models.
The modernization project will allow Easytrieve 11.6 (NEWFUNC=Y) to generate code for the latest model (z16 / ARCH(14)) and future models. The plan is not to bring the support it to 6.4 nor 11.6C at this point.