When I used the seed 1201872064 to generate worlds in 0.9.0 and in 0.15.0,I got two different results:in 0.9.0 the village has a stronghold under its well,while the 0.15.0 one is a zombie village,with no stronghold.So I think zombie village doesn't generates a stronghold is a kind of bug.
I upgraded to 0.15.4 and test again.My Android device does generates a stair,but links to no stronghold,shows as p3.But Win10 world links to a stronghold,shows as p4.(The pictures will be in the correct order if you sort by date.)