Hey there! I'm a local mapper from Scotts Valley, California. I see that you requested a review of this changeset, so I'm giving it a review.

In general, some roads may not need to be explicitly marked as being bikeable. I'd recommend reading the OSM wiki page about "OSM tags for routing/Access restrictions" https://wiki.openstreetmap.org/wiki/OSM_tags_for_routing/Access_restrictions.

In general, certain road classifications have certain default access restrictions that are generally believed to be what routers should interpret. Of the roads that you marked, it appears that it merely confirms what the default expectations are in the US.