PJ2;
Yes, and for ALTN 1 as well. This change was made around 1997.
The FCTM is a CX one dated June 2005, and it seems strange that it made reference to the >10 sec ADR disagreement resulting in ALTN2 only.
The notable difference between ALTN1 and ALTN2 is the Roll Direct, and it is possible that the A/P cannot be re-engaged in that condition, i.e. PRIM requires a hydraulic reset on the ground. The RTLU can be reset with slat/flap extension below FL200.
Hopefully someone can identify exactly when and why the A/P re-engagement is inhibited.
EDIT :: My crib sheet has the following on Law reversions:-
Alternate 1:The pitch attitude (Theta) protection is lost. High speed and stall protection are alternate.
Alternate 1A:In addition the stall protection is lost.
Alternate 2:The pitch attitude is lost and high speed and stall protection are alternate. In addition the lateral normal law is lost and replaced by the lateral alternate law (roll direct and yaw alternate).
Alternate 2A:In addition stall protection is lost.
Alternate 2B:Pitch attitude, high speed, and stall protection are lost and the lateral normal law is replaced by lateral alternate law (bank angle protection lost).