absolutely ambiguous annona, deserves a second, and third look you bet!
considering the stage of ripeness and quality of flesh, i too am veering towards atemoya.
squamosa pulp generally gets thinner and way more translucent at that stage of ripeness(considering that the rind of the specimen is no longer green and already parched, and the flesh is a bit sparkly with juice-- no longer cottony) , and noticeable here that the flesh closest to the skin is still rather thick and still bright white despite the late-stage of ripeness, which does not occur in true squamosas. Squamosa seed units at that stage of ripeness will typically be seen almost sitting directly on the rind.
and as shown by @Lids above, atemoyas may have exteriors that look exactly like true squamosas, although also possible that true squamosas may have exteriors like atemoyas.
the characteristics of flesh seem to be better determinants
yeah, green ones are most common squamosas. Have grown reddish squamosa’s which look really pretty, but taste the same