WireGuard is a protocol that, like all protocols, makes necessary trade-offs. This page summarizes known limitations due to these trade-offs.

Deep Packet Inspection

WireGuard does not focus on obfuscation. Obfuscation, rather, should happen at a layer above WireGuard, with WireGuard focused on providing solid crypto with a simple implementation. It is quite possible to plug in various forms of obfuscation, however.

tl;dr Read the docs.