In an interview from fairly early in X-Force, Percy responded to fan complaints that 'people who say Beast is lovable have only read a few comics'. In which I'd respond 'I'd say that of you'. Percy only knows how to write shock value and gore, characterization be damned.
Percy kept teasing explanations for Beast's behavior that were never followed up on. First it was this might not be the real Beast, no, he's being controlled, no, he's been driven insane from his traumas, no, he's just always been evil.
I'm really hoping they go with that theory that he was switched with an AU version starting about 2012. Is that what you were referring to? .