Seems to me there is a post-Jose effect where players overperform for a long period when he leaves. It may be that his mantras of tactical discipline actually leave a permanent benefit on the player.
I once had a bullying boss back when I worked at the BBC whom everyone loathed. Given a few more months she would have decimated the programme she led, as morale and energy levels collapsed. Fortunately the big hitters on the show forced her replacement, and there was a surge in creativity and energy afterwards. Still I felt like I learned a lot from her nevertheless, and she changed my game technically. But I still wouldn't p#ss on her if she was on fire.
That's just my little anecdote, but I feel something recognisable to me happened at Chelsea, and, arguably, at Madrid after their bully left. Perhaps that's what's happening here.