I'm not and never have been a dub. I hope that my views won't cause offence - none is intended - and they probably apply equally to most 'committed' fundies.
I have experienced many times conversations with JWs where initially they come across as confident, informed and knowledgeable conversationalists. But inevitably at some point one can almost see the eyes glaze over and they go into 'robot' mode when rational discussion (and the ability to reason and accept, or at least consider, alternative points of view or be open-minded as to evidence) ceases.
In RL, IME people can have an open discussion however different their views and however heated it may get, at the conclusion they can agree to differ and may even concede that the other may have raised some points worthy of consideration. Without exception, my conversations with dubs have concluded with them (metaphorically) putting their fingers in their ears and singing 'la la la la, can't hear you' which is the equivalent of 'if I close my eyes you can't see me'.
I appreciate that this is only one area of 'social skills'. My take on the question posed in OP is that while WTBTS training MAY enhance a dub's capability to make an initial approach for conversation the actual 'social skills' to continue to a 'normal' conversation are severely limited by the 'programming' inherent in that same WTBTS training.
No offence intended.