BLITZCRANK IS FINE

He was sitting at a healthy 50~ ish percent winrate prior to your buff. You already buffed his ult. The current hook range buff was unneeded and while I won't go as far as to call it OP, it's obnoxious and uncalled for. An extra 100 units might not mean much to most, but it's certainly enough to make your opponents a bit more wary of you and give you some extra lane pressure which most competent Blitz players don't need.