This is the intent to remove TLS 1.0 and 1.1 from the default TLS protocols on the server-side.
This change will affect your deployment if it's using default minimum TLS protocol version (i.e. not configuring tls_minimum_protocol_version) and it's accepting incoming TLS 1.0 or 1.1 connections:
$ curl -s localhost:9901/stats | grep -E "^listener.*.ssl.versions.TLSv(1|1.1):"
listener.<address>.ssl.versions.TLSv1: 1
listener.<address>.ssl.versions.TLSv1.1: 1
(This works only with Envoy v1.9.0 and newer)
ETA: 1.13 (i.e. early 2020)