Something just occurred to me. Cindy said that Negan killed all the men and boys under 10. That implies that Oceanside still has boys under 10 at their camp.
So where are they?
Something tells me that Negan isn't the one at fault here. perhaps the colony decided to kill the men themselves.
I thought the samething plus their only a 2 weeks walk away from Alexandria I'm sure Negan's crew would have found their camp easily by now.