You just kinda contradicted yourself here. If MS/MX are to get the newer tech first, why are the 2170s being produced for the Model 3? Everything quoted above is also pure speculation your part. Nobody knows if/when MS/MX will get the new 2170 cells.
Pack redesign **either way** is pure speculation as well. You can't assume they redesigned for 2170, just as much as one can't say that the pack can't handle 2170.
Rather than playing exercises with semantics, just look at Elons statements regarding new tech in S/X.