The reason it was never fixed is simple, it never existed (as advertised). Having played with the editor and setup some AI routines, it is blatantly obvious that there is no bottled up, or crippled 'killer AI' capable of decision making there.
Their claim that it was 'too clever for it's own good' was a ploy to feed the myth.
Further, there's lots of test cells accessible in the editor some of which are E3 style demos - all (unsurprisingly) scripted. Amusingly, there are also some very cool (but demanding) particle/lighting effects listed, and used in these demos/test's, but none are actually instanced in the main Oblivion cells. They are all prefixed 'E3_fx' though...