Well I wouldn't say that there are any locks per se.
However I think you're too confident with your list:
1) Bolt will have a very rough time in the 100m and probably won't win.
2) Kiprop has been relatively consistent in the global stage but he can be unpredictable (in a bad way) as he's shown in diamond league events
3) Dibaba is now probably off the juice after the recent events
Ayana and Semenya are close to locks no doubt.
From statistics alone, little Kipruto the Steeplechaser is undoubtedly the dominant performer in track this year and as close as you can get to a lock.
He handles the pressure well, isn't afraid to run and is consistent year round.
He's also the Diamond League winner (5/5 should do it I suppose), and will likely have an Olympic Gold and sub 8 clocking this year.
If I was a rich guy I would bet 10k on Kipruto just for fun, odds are likely better than a coin toss.