Other than highway=motorway, the highway=* key does indicate a functional classification of sorts, just not necessarily the classifications that Caltrans has determined using the FHWA’s framework. There are various reasons for this, including different incentives like funding levels.

There is a separate https://wiki.openstreetmap.org/wiki/Key:HFCS key for indicating the official FHWA/Caltrans functional classification of a given road. Mainstream renderers and routers don’t use it yet, but that’s because the mappers who added most of this data are no longer active within the project. You could help to revive this form of mapping, at least here in California, where we can copy from DOT maps without infringing on copyright.

The choice to depart from FHWA/Caltrans functional classification is not mine or willkmis’s, but rather that of the project as a whole. If you disagree, you need to take this up with the wider community on the forum: https://community.openstreetmap.org/c/communities/us/78 . Otherwise, your work is inevitably going to get undone by passers-by in a matter of weeks, but much more haphazardly than the systematic tagging that willkmis did.

The Trunk Road preset’s lack of a bike lane field is a simply an oversight. Please report issues like this in https://github.com/openstreetmap/id-tagging-schema/issues . Thanks!