Yes, the ipv6 authorized-managers is correct. I connect to the switch via ssh from the same host I try to use snmp from. The problem also occurs if I do not set the management ACL.
== Update ==
I have additionally tested SNMP Traps, over IPv6, they work (i.e. I can see snmp-trap packets in tcpdump on a linux host over ipv6). Only the snmp polling, which is supported according to IPv6 Management Guide, and another IPv6 Guide for the WC.16.05.
The same SNMP for IPv4 features is supported over IPv6:
• Access to a switch using SNMP version 1, version 2c, or version 3
Feels like no one actually tested it.