Can a demon can teleport in a silence spell area?

@LichenSuperfood @JeremyECrawfordJust trying to figure out if a demon can teleport in a silence spell area? It’s ‘magically’ but not a spell? only if ability specifies it must be able to speak or it specifically says it is casting the spell

— Mike Mearls (@mikemearls) March 21, 2016