Native code was never gone forever from the Nspire Clickpad / Touchpad / CX / CM series, which has a better security design than the TI-eZ80 series, and it's publicly documented that there's arbitrary code execution on the CX II. More generally, time and again, native code is always made accessible (again) on all closed platforms, sooner or later. Therefore, you should not think that assembly programs will be gone forever on the TI-eZ80 series - that just doesn't match what happened and will happen on other platforms
Also, older non-Python 84+CE / 84+CE-T / 83PCE calculators whose boot code version is older than 5.1.5 do not have downgrade protection.
@Cemetech staff: for the sake of users, Cemetech really should add big fat warnings against OS 5.5+, like TI-Planet and CodeWalrus did. You didn't do it before to raise awareness, it's your choice, but now, it's high time you did it.