For me personally, not really. I love watching the knuckleball (used to love watching Candiotti and Wakefield too).
Aside from that, Dickey will almost certainly outperform his contract, so the only thing even close to being negative imo is losing Syndergaard (don't really mind losing d'Arnaud). I also think we'll see a much better Dickey next year. He only had his full velocity for a few starts at the end of the season this year.