Bitcoin's peer-to-peer network has run over plaintext connections since 2009 — anyone on the path between two nodes could see which node was asking whom for which transaction. BIP-324 (v2 transport protocol) adds opportunistic encryption and obfuscation to the connection itself, negotiated automatically when both peers support it and falling back to plaintext otherwise. It doesn't hide that you're running a Bitcoin node, but it does stop a passive network observer from mapping which node originated which transaction just by watching the wire.