I am somewhat familiar with the 336. Newer or older, I don't have much trouble with either vintage. I appreciate the fondness for the old rifle, but I also lack the problems sometimes talked about for the newer models.
I am pretty sure it is an overblown internet myth. Early on, there were some reports of buggered screws and mediocre wood-to-metal fit. When you start looking for comparison pictures, you find a few of machine marks inside
the reciever where the do not interfere with operation. Interenstingly, a lot of the pictures for early transition guns show targets where the holes are touching.
I have looked at several Remlins in the last 6 months and they all look great. The actions have functioned smoothly and the triggers were about like my 1974 Model 336.
One of the few things I don't like about gun forums is the propensity for people to repeat as fact what they have no experience in.