That's right. When exposing new interfaces we typically don't expect any compat fallout, but I took a quick look at "
RTCPeerConnectionIceEvent" in httparchive, only 9 hits. All except one in lists of interfaces, and one was feature detection for WebRTC:
if ("RTCIceCandidate" in window || "RTCPeerConnectionIceEvent" in window) { ... }
Since RTCIceCandidate is already exposed, nothing will change.