ttdtt -
Maybe something has changed recently. The use of script readers for conventions has been reported for several years. This was not the case when I was giving public talks back in the 1960s, but I've had several ex-elders and former relatively high ranking brothers who were actually assigned to be script readers at district and regional conventions.
I do believe that this is a relatively new development (since 2000, probably) - the script readers sitting off to the side or behind the curtains at assemblies. I have also heard that brothers assigned to give the 30-minute public talk during the weekend meetings are also cautioned not to go off script or face the loss of that privilege.
Much has changed since the era of 55-minute public talks developed and given by mature brothers who filled in the gaps and added some of their own experiences to the outlines that we were given.
I attended a recent convention near my home a few years back. It was the Saturday afternoon session when they first released the first cartoon DVD for children (2011?). There was a group of 15-minute presentations that were interviews with local full-time pioneers describing how they overcame their money and personal needs in order to put in 100 hours a month - or whatever it was at the time. I could tell that the those interviewed were either reading their notes or had memorized their presentations word for word. It all just seemed so rehearsed and unbelievable, but I thought that was my "inner apostate" talking.
Later I happened to meet a former elder who had left the JWs at a meetup. I mentioned my observation. He told me how the process worked and about the offstage script checkers. Later, I met another former elder who told me that the script-readers were real. He also mentioned that sometimes the presentation by the "pioneers" really does not represent their lives (often the same exact "pioneer talk" is given at several different convention locations). The local elders recommend JWs who are serving as pioneers or elders and then they are given the script to read and told that they are representing other exceptional pioneers - not themselves personally.
It's all very scripted. I still can not get over the sing-song style that most JW speakers use now - far too practiced and rehearsed - just like the JW.org videos and training sessions on disk.
JV