I think they are softening up on this viewpoint. The July 15 2015 Watchtower explains their latest light on the matter. This was the article that had them saying there would be a 'rapture' of the anointed.
In that article they say that the GT will be "3 Soon, very soon,"
Although they state that they don't know the exact order of events they do state that the beginning of the GT starts with Babylon the Great (false religion/religious organizations) being destroyed but there will be some who leave their religions
even some of the clergy will abandon their religious course and deny that they were ever part of those false religions.
Here's what they say about the message changing during the GT
9 This will not be the time to preach the “good news of the Kingdom.” That time will have passed. The time for “the end” will have come! (Matt. 24:14) No doubt God’s people will proclaim a hard-hitting judgment message. This may well involve a declaration announcing that Satan’s wicked world is about to come to its complete end. The Bible likens this message to hailstones when it says: “Great hailstones, each about the weight of a talent, fell from heaven on the people, and the people blasphemed God because of the plague of hail, for the plague was unusually great.”—Rev. 16:21.
In the article they explain
we cannot expect that the future interruption in the great tribulation will result in an influx of new believers.
An influx means a great number of people so they are leaving their opinion open to the idea that there will be some new believers.