if they remove the gold stats on tools that we already got then people will quit en masse, this game would die within a few months of that happening because its not fair to the people who worked hard to get those tools and reforge them all.
this actually is an issue of 'play long enough and youl catch up'. The CN version has the stat items available as rewards for TI(might drop elsewhere too, I'm not sure) so eventually you can get all of the stats that we got from Red Gourds it will just take some time, and while you wait you can get you're tools leveled up. It takes about 2.25 weeks of TIs to get 1 tool from level 18 to 19, which means minimum a year and a half to get all your tools from 0 to 20.
People who want gold stats can make do with UT stat items in the mean time while they level their tools and wait for more stat items to become available. Its not like you can't work on the ninja tool system at all while you wait.