Delphi-XE4 understanding threads count

Question

Since my iOS app terminates (if running in debugger, the app simply freezes without any errors) after some minutes of intensive use, I started looking into possible reasons why the app would simply suddenly close down. (But always first do so after some time.)

I create lots of shortlived threads that are set to terminate when done. (I use FreeOnTerminate := True in constructor.) However, in Delphi IDE | Thread status the threads seem to live on after execute has run.

So in debug window, I have e.g. 100 threads with State=none and Status=unknown. Am I correct in assuming that means the threads are not completely freed/gone?

For reference, demo code:

constructor TMyOnlineThread.Create(...) ;
begin
  inherited Create(False);
  //--
  //...
  //--
  FreeOnTerminate := True;
end;

destructor TMyOnlineThread.Destroy;
begin
  //...
  inherited;
end;

procedure TMyOnlineThread.Execute;
begin
  //--
  // Single task. No while loop or anything like that.
  //--
  if (...) then
    begin
      if Assigned(FOnDone) then
        Synchronize(MyCallBack)
      ;
    end
  ;
end;

procedure someothercode;
begin
  TMyOnlineThread.Create(...);
end;