The use of language in general makes it more difficult for incarnate beings to use ósanwe, apparently, so we can definitely make this 'not a thing.' But....it specifically would still exist in the case of close friendship, kinship, and great need....I think this points to Fingon and Maedhros as two people who should definitely be able to make use of this ability.
I've been wondering for some time how Fingolfin's host is going to find out they've been abandoned - are they going to be able to see the burning of the ships across the ocean? I realize it's further north and the shores are closer together, and that elves have better vision, and that the world isn't round yet (so no curvature to block the view). But still. It doesn't seem possible....but if Maedhros is able to let Fingon know that the ships are being burnt...well, that's one option.
I've been wondering for some time how Fingolfin's host is going to find out they've been abandoned - are they going to be able to see the burning of the ships across the ocean? I realize it's further north and the shores are closer together, and that elves have better vision, and that the world isn't round yet (so no curvature to block the view). But still. It doesn't seem possible....but if Maedhros is able to let Fingon know that the ships are being burnt...well, that's one option.