MandM did not refute or confirm an aether, theory of;
the very first page of their report mentions the regular anamoly
that they found in the experiment.

anyway, since our comprehension of the properties of atoms
in "free space, whose index of refraction is nearly one, like air"
the aether is of no use, what ever. for example,
to explain the ttoally wavelike behavior of light,
adduced in Young's two-pinhole experiment etc.

If Michelson would have predicted an aether- relativity would have lived