Okay, so the question was, should the "Summon Demons" be on the Warlock list.
4E: Warlocks have Infernal Pact, Pact with a Devil and Wizards have Summon Demon Spells, but Warlocks don't (and this made sense for that edition's fluff)
5E: Warlocks have Fiend Pact, which can be with a Devil...