There is a precident for the JWs becoming more hard-lined: The Exclusive Brethren.
Prior to 1959 the Exclusive Brethren, whilst conservative, tended to have a more open outreach and even allowed some fraternizing with non-members. However, following directions from their leaders in 1959, they suddenly slammed closed the doors, introducing beliefs such as: Refusing to eat meals with anyone who was not a member and (this makes me sick) automatically breaking up families if one spouse questioned the authority of the leaders. They also kicked out modern technology such as radios and TVs. Their excommunication policy is a model in mean-spiritedness. When they excommunicate you, boy are you treated as one who is dead: You will not even be notified if anyone in your family is ill or has died.You may find out - by chance - several years later. They have lots of beleifs in common with the JWs: They are also pacifists, do not become involved in politics (hence, they don't vote), they have several meetings a week and on weekends, spend long hours in cramped halls; they avoid the language of "Christendom" which is reviled. The woman are not allowed to cut their hair, but must wear scarves, and the men have a mousy, 1950s rural look about them. Now, true to expectations, the only growth they report is from within (i.e., children born into the religion.).But they 're not worried: There are several thousand here in New Zealand alone, and there are always huge numbers of late model vehicles parked around their unnamed fortresses (another similarity: they hate the word "church").
From a reasonably outward looking group, to an insular, self-absorbed group - all within less than a generation.
Oh, yes, the Watchtower has a ready-made model to follow, if the bleeding exodus continues much longer.