I am not aware of any plans at this point in time to make band steering part of the official baseline feature set. The usteer daemon is a paid development effort to implement band steering capabilities on OpenWrt, but afair it was not implemented with the goal to make it part of the next release.
But given that it exists now there likely will be some effort to either make it default or to at least make it a well integrated installable option. But no definite timeline or decisions for that.