As someone who is predominantly a Rieekan player, I can say that there are ways to deal with him. More so than most other commanders, losing Rieekan tends to decimate his fleet. There have been several matches where I would have lost hard had my opponent concentrated on destroying the ship Rieekan is on. Things snowball quickly once Rieekan dies, and suddenly TRC90s and MC30s are no longer guaranteed their return fire. Putting Rieekan on a flotilla can make this difficult, but massed Bombers with Intel could chew through a flotilla pretty fast, as can anything with H9s. Deploy carefully, avoid Superior Positions or Solar Corona, and you should be able to put yourself in a position to kill Rieekan.
He's been my favorite commander since he came out (back before he was considered OP), so I really hope they don't nerf him. I could stomach a small points increase, but I hope his ability stays intact. Next wave(s) might offer some counters too.
Now, a question for the court of public opinion. I can see how running a current Rieekan's Aces list would be frowned upon in a local meta, but he's still my favorite commander (mostly for capital ship play). What if I run him old school, just using pre-CC Aces? Is that still uncouth?