The draft considers FIPS 203 to be normative. Therefore FIPS 203 forms part of this draft. You can't implement this draft without first implementing FIPS 203.

FIPS 203 doesn't care about side channel resistance, per my other comment at [1]. And this draft doesn't do anything to tighten the constraints on how FIPS 203 should be implemented to provide side channel resistance.

[1] https://news.ycombinator.com/item?id=48811887