I don't see any announced changes in the last two years on the news portal. But as far as the study process goes for the exams I would do this.
Currently posted objectives are your main checklist. These are the topics from which the question pools are taken.
http://www.juniper.net/us/en/training/certification/resources/jncis-ent/
The free guides you are referring to were part of the Fast Track portal. Looking at the training site it looks like this portal has been removed now. So I would guess the material is considered out of date. There are other general resources listed on the old page in the mean time.
http://www.juniper.net/us/en/training/fasttrack/