Ya, you seem to have missed the deadline. I just looked at that provision in the Code. Opportunity Zones are areas that are depressed, crime-infested, places past their prime. In other words: areas needing redevelopment. You might check out Holyoke, MA. Just up the road from my hometown, Springfield, MA. Both are crime-toilets these days. If you are central or eastern MA, maybe something a little closer to home.
Ah! I found a Statewide map. Includes even PROVINCETOWN!
https://www.mass.gov/info-details/opportunity-zone-map