potentially, but i doubt it.
most plants can be propagated from leaves like that, but the success rates vary greatly. hygro will grow just fine from a fraction of a leaf, and if left floating start growing emergent tissue. but most other plants just rot.
if you were to place it in vitro it would do fine, but why bother for glosso.
if there are roots appearing then I bet they would start propegating. But personally, I would try the leaf emerged first, then once a good chunk has been made, I would put them back under water. I just think that it would be difficult for you to get the glosso leaf to stay down.