Just wanted to pop in and let everyone know that the fix for this issue is present on the 1.13.6 PTR now and I’ve gone ahead and updated the PTR patch notes thread here with this information.
Similar to the issue with Improved Weapon Totems, this trinket did behave in this incorrect way throughout the entirety of its availability during original World of Warcraft. Much like the totem issue however, this was not intended and the issue was fixed in later versions of the game. As a result, we are making a fix to bring this item in line with its original intent.
Thanks for the reports about this!