LAND 3 to LAND 2 reversion response
The answer depends both on company policy and Op-Spec approval.
That is the reason why some operators elect to simply set the RA bug at 50' HAT (or equivalent, for the specific SIAP, underlying terrain, and TDZ) and then for a LAND 3 Reversion to LAND 2 simply convert use of a (pre-briefed) Alert height of 50', instead to a revised DH of 50', with no need for any bug changing, ...and only the RVR limits being adjusted, as needed for the new minima (which is also pre-briefed).
That technique and procedure facilitates the ability to continue the approach, when WX may be deteriorating, and avoid an unnecessary MAP and ~15 minutes of more flying, while snow is accumulating and mu is decreasing, or the fog is getting worse.
Bottom line is that it is what the operator's policy is, that sets the response. It depends on what the operator is training to, and what have they applied for, and what do their Op-Specs permit.
Again see FAA AC120-28D (for Cat III) and AC120-29A for similar issues with Cat I and Cat II use of LAND 3 and LAND 2 modes.
Note: Similar questions can arise for various aspects of using AIII mode with a HUD, particularly with respect to known momentary anomaly annunciations due to confirmed temporary ILS beam anomalies (also note with GLS there are virtually NO beam anomalies ever.... GLS is simply amazing to see how much better it is than using an ILS for approach).