I would think a peer-to-peer system would not be exempt from this legislation, particularly given my understanding that the EU courts do not look favorably on gotcha-style analysis of laws that are limited to definitions of words used being twisted to claim "I'm unregulated". If you are a developer who works on a chat client as part of a decentralized service, I'd expect both you and all of the people running the network to suddenly become service providers subject to this law.