I't because the pilot can use the LOC deviation bar for deceleration, same for aborted take off during LVP. We are trained to abort take off if you go into zero zero prior to V1 using as only referrence the LOC deviation bar, therefor the same principle applies for CAT II. You require the t/d zone for the landing but mid and roll out are not required, just advisory.
Can't say I agree with it but that's how it is.
Cheers
Snails