How will Consul clients running 1.2.3 be impacted after upgrading Consul Server 1.3.1 to 1.6.1

Hi,

As I’ve understood per Consul changelog, breaking changes from 1.3.1 to 1.6.1 are only on for Consul server, but clients running let’s say 1.2.3 version will not be impacted? They’ll still use current ACL tokens that are backward compatible?