If I remember rightly, it varies with versions too. In my 365, this code:

   Dim u(1 To 2, 1 To 70000)
   Dim v
   v = Application.Transpose(u)
   MsgBox UBound(v, 1)
rather worryingly shows 4464 as the upper bound of the first dimension of the transposed array. So it appears to have done some sort of Mod 65536 and resized using the remainder, keeping the data from the start of the original array.