Guillaume, you seem to suggest it for every list to be renamed/splitted. This is an ugly leftoff from times when there was no separate domain for lists and this suffix was useful for differentiation between lists and normal email addresses. Now it's not needed and is actually not used by new lists.
Topic on Talk:Development process improvement/Communications recommendations
Hi Max. I know it's not needed any more :) I think it has become a habit for many Wikimedians, and that's probably the reason why even some recently created lists have the -l suffix. It's really a detail and I'm fine either way. Feel free to edit the page (not only for that, by the way).