It seems most melee abilities are at least a 7m range. Veiled Strike and morphs are only 5 according to tooltips. NB needs a lot of help in various ways, but it seems this should be a minor QoL change, in addition to other buffs.
Ahh it does look like all single target instant melee abilities for non-DKs are 5m. I was looking at Scythe and Brawler and not looking at Executioner.