Yep, some people got an upgrade item from a drop while “filling the bar” for the weekly on Siren Isle and got a second upgrade item by doing the quest Juicing Up and Storming Out, so they got their rings to 652.
That doesn’t seem to have been intended and was hotfixed by the time I did my Siren Isle stuff… I did get a raw citrine upgrade from a drop before I got the Jucing Up quest, but when I completed the Juicing Up quest it only gave me iron, not a second raw citrine (so my ring is 649 which seems to be the intended cap).
Not sure if they will reduce the ring back to 649 for those that took advantage of this (probably not), but that’s how some are at 652 this week. See this poster that got their ring to 652…