The thing is this very process has been in the game since reputation was introduced with the Return of the Gree in patch 1.7 back in Feb. 2013. You could run the Gree event on every character, hit the max rep for week and keep collecting tokens as you keep playing the event.
I did this on every character I had that could run the event every day and was using rep tokens for 6 weeks after the event ended just so I could get to legendary to get access to the first true legacy modifiable weapons and offhands as quickly as possible. I've been maxed on the Gree reputation since April 2013, I still enjoy doing the event once and while, just depends on what I am doing when it comes around.
EA/BW never stopped the ability to stack up rep tokens all these years so I don't see how it could be an exploit, they've known about this since the beginning, intended or not they left it working that way. The weekly cap just slows you down on getting the reputation track ranks and access to any special vendors, not collecting the tokens you earn by completely missions. If the weekly cap stopped you from earning tokens then that would be a reason to stop playing the event since you are no longer getting rewarded with one of the main reasons to do the events.
They could have changed or removed the weekly cap, the effect would be the same in end. In fact they did nothing about this token collection even after conquest was introduced and the conquest points for using a daily reputation token was set at such a high amount and has been that way for years. Why did it become such a problem now that the points needed to be nerfed? I have my thoughts.
Add me as one more that is not happy with this stealth nerf and reasons given and after 12 years as a subscriber, this is one more "bad decision / response to player feedback" straw added to the camels back, and it's cracking if not breaking. For first time I am reconsidering the state of my subscription going forward.