yes you can, its top left, there is an input field. Not the best ui, i know, but you can rename them as much as you like :)

I couldnt see how to do it? can you rename existing ones?

yes you can name the teleporters, the map markers dont show the name but the buttons yes - there is an input field, that is saved automatically, just type your name there

Oh and its working great on our dedicated server, on the new dlc map, though we have yet to fully test

Teleporters are an awesome addition.
Is there a way to name them?