I would be surprised if they ever intentionally fade away from trying to present a sense of urgency for the end of the world. People are much more productive when they think it will affect their own life. It has always been so profitable for the organization. For example, when Fred Franz merely suggested a possibility of 1975 in the 1960s, it exploded into a frenzy. Once the Organization saw how profitable it was, they kept it going and even fueled the fire.
So, when there was a falling away following 1975, what did they do? They had a house-cleaning at Bethel in 1980 and claimed the falling away between 1975-1980 was due to apostacy at headquarters.
No, I don't think they are likely to let go of the sense of urgency for the end of the world until they are ready to 'cash in their chips' to phrase it in 'apostate' terms.