I found this very interesting read. Pages 47-48 deal with the Alpha Protection Mode and contain the paragraph below. It is mentioned in other areas of the report as well though I misquoted 100 feet instead of 150. I agree that in Alternate Law it shouldn't have the normal protections as you stated. Still some tweaking to the software after the fact by Airbus I'm sure.

https://www.ntsb.gov/investigations/...ts/AAR1003.pdf

"1.16.1.2 Airbus Simulation

Airbus performed a simulation of the last 300 feet of the accident flight, which indicated that the airplane was performing as designed and was in alpha-protection mode from 150 feet to touchdown. The Airbus simulation indicated that, from 1530:36 to 1530:43, the flight control system attenuated the effect of the pilot’s airplane nose-up (ANU) sidestick inputs below 100 feet radio altitude. "