Is there any link at uscis website which states that they accept I-485 if the EB-2/3 priority date is earlier than the DATES FOR FILING OF EMPLOYMENT-BASED VISA APPLICATIONS?
In https://www.uscis.gov/visabulletininfo, USCIS will indicate on this page that you must use the Application Final Action Dates chart to determine when you may file your adjustment of status application.
For Employment-Based Filings:
You must use the Application Final Action Dates chart in the Department of State Visa Bulletin for March 2016.
You must use the Application Final Action Dates chart in the Department of State Visa Bulletin for March 2016.