A county legislative authority shall periodically comment to the commission in writing concerning the authority’s perception of the adequacy of service being provided by regulated franchisees serving the unincorporated areas of the county. The county legislative authority shall also receive and forward to the commission all letters of comment on services provided by regulated franchise holder(s) serving unincorporated areas of the county. Any such written comments or letters shall become part of the record of any rate, compliance, or any other hearing held by the commission on the issuance, revocation, or reissuance of a certificate provided for in RCW 81.77.040.