Do glass/stones migrate to the surface of lawns?

I recommend you remove what you can see - its a bit of a cheek that you've ended up buying topsoil full of broken glass - perhaps picking off whats on top and then raking lightly might reveal more. Then lay the turf - it shouldn't surface on top of the grass, but if there's to much of it underneath the turves, and some of it larger pieces, it will prevent root penetration into the topsoil by the turves.

I'd also complain to whomever you bought the topsoil from and ask for a partial refund. There should not be broken glass in topsoil.

I think it was Darwin who observed that the activity of earthworms buried all the stones in a field over a period of ten years or so. (in meadowland) So if you have earthworms then eventually all the bits will disappear. I know you won't want to wait ten years, but from what you say you are burying the glass under the turf so the chances are the stones and glass are more likely to go down than come up. Stones and other solid objects only come to the surface in regularly cultivated land, not in grass. Otherwise we'd be falling over stones every time we walked through a meadow!

stonesdo indeed slowly make their way up to the surface. some geological feature i seem to recall. my geography teacher likened it to making pastry, shaking the bowl and seeing the larger lumps of fat surfacing, ready for more rubbing in. [he was married to the cookery teacher and used cakes cooking to explain volcano shape] now why do i remember that from 35yrs ago?

Yeah stones certainly come to the surface in our ground...