This chapter shall not apply to any county, city, town, school district, or fire district activity, regardless of how financed, other than a utility or enterprise activity as defined by the state auditor pursuant to RCW 35.33.111 and 36.40.220 and upon which the tax imposed pursuant to this chapter had previously applied. Nothing contained in this section shall limit the authority of the legislature to authorize the imposition of such tax prospectively upon such activities as the legislature shall specifically designate.