Test Island was a "Test Phase" to anything we wanted to add. But now we've changed the way TI will work and how we will use TI for the game.
TI is now a Test-Before-Adding (TBA), technically it always was a TBA map. But now we will only test things that we're not really sure if we want to add it or not. Maybe because it's something really difficult or it may cause problems in the game. So TBA Map a.k.a. Test Island will be a Test-Before-Adding-If-We-Are-Not-Sure-If-We-Want-To-Add-It (TBAIWANSIFWWTAI) for short.
~ Ryan