Making import x absolute seems to me to cause more pain than gain—including the change of habits.
More importantly, because of the change in habits, too much planned breakage might slow the transition to Dotty—people are trying to keep lots of things compatible, and there will likely be some unplanned breakage in corner cases.
(I also wonder how soon we can rely on scalafix, but I asked this separately in Scalafix v0.3 released - #2 by Blaisorblade).