5G Evolution would be a name for 6G (whatever that is)
The orign of the name "LTE" as in Long Term Evolution was a 3GPP committee which wanted to set a 4G standard but whose remit was only 3G, so they discussed "3G LTE" by which they meant "4G". 4G was the long term evolution of 3G so 5G E, would be an evolution of 5G, as in what comes after, and it's far too early to think abou that. Indeed we may never get 6G : https://www.theregister.co.uk/2014/05/21/ee_and_prof_say_6g_mobile_will_never_exist/