The saved gear sets used to update their weapon level in the name upon save. After the patch 2.1 landed, the naming scheme changed, and now the item levels in the saved set names do not get updated on save, but only on the English client; or at least it is working correctly on the Japanese client.

It's possible it's been changed to be a simple replacement of "Lv<<number>>" with "Lv<<new number>>", since that's the default item level string on the Japanese client, but I haven't tested it.