Yes, i would think oto fry too. I have not spawned Galaxy Rasbora, but given that species is a cyprinid the eggs would be scattered (as in the moss), and if some survive and hatch, the fry would be free swimming; I see this from several of my characins species in well planted tanks. My Diamond Tetra, originally seven, now number 35 or more (difficult to count such active swimmers), and in another tank the Lemons have increased from the original eight to 32 or 33 at last count. Over a year or more in both cases. By contrast, Oto fry would cling to surfaces.
Several years ago I had three otos in a 90g tank that was thick with plants. I rarely saw them, given their natural ability to remain motionless on a plant leaf or chunk of wood and be unnoticed. Then one day I saw them and coounted them...there were five. Obviously the three had spawned, and two survived and grew; they were just a bid smaller than the original three, noticeable only when I could count all five at the same time, which I did. Another case of fry being able to manage in an established tank with plants. There is microscopic food available, and for otos this would be the biofilm that forms on all surfaces covered by water, where they can graze on infusoria, algae, etc.