Prior to the publication of any notice of hearing for any appeal or application, the Zoning Board of Appeals shall transmit a copy of said notice to the Planning Board with the request that the Planning Board submit to the Zoning Board of Appeals an advisory opinion on said application or appeal, and the Planning Board shall submit each advisory opinion to the Zoning Board of Appeals within 30 days after receipt of such notice. Failure to submit such advisory opinion to the Zoning Board of Appeals within the time above set forth shall be deemed an approval of such application or appeal by the Planning Board.