I believe that was what was meant - this issue of NTT predated Perez's Wonder Woman - it was pre-Crisis. New Teen Titans #11-#13 (1981 cover dates).
NTT - Island.jpg
I don't prefer any magical restriction on men on the island. I think it doesn't work well with Steve. And I don't like removing the element of choice from the Amazons. And if they need to fight appropriately when invaded, they can and will do it (with no magic to solve the problem). Some magic hiding the island is more acceptable, but not required.