Hi CONF iture,
It simply does this rather well. No promise of achieving aMax - only of not exceeding it.
FCOM 27-20-10 Protections.
"HIGH ANGLE OF ATTACK PROTECTION
Under normal law, when the angle-of-attack becomes greater than αprot, the system switches elevator control from normal mode to a protection mode, in which the angle-of-attack is proportional to sidestick deflection. That is, in the αprot range, from α prot to αMAX, the sidestick commands α directly.
However, the angle-of-attack will not exceed αMAX, even if the pilot gently pulls the sidestick all the way back. If the pilot releases the sidestick, the angle-of-attack returns to αprot and stays there."