Yeah in Japan they took things in another direction completely: they ditched Rebirth and had their own 'pilot'/intro for the Headmaster series.
Crazy as it sounds, by the time 1987 rolled around the Transformers series in North American had completely dropped in popularity [iirc the stat is kids' toy franchises have a shelf life of 3 years, so they were already ahead of the curve] so even though there was an order for a fourth "season" of the animated series, it was originally suppose to be a five-parter and done, then got chopped down three parts...which explains the utter character dump.
http://tfwiki.net/wiki/The_Rebirth
