Yeah, had it removed.
I'm pretty sure it's the same thing that's slowed down Dwyane Wade. He had a meniscus removed as well and has said before that he regrets it.
Not sure if Wade's problems are a common result so maybe CP3 will be fine, but we'll see.
Yeah removing the meniscus as opposed to repairing it has really slowed D-Wade down. Another factor is that Wade's game was predicated on getting to the hoop and he took a lot of contact - his knees just can't take the beating they did in his younger days. CP3 slowing down will show up most on defense though - he doesn't have a prayer of stopping younger guards because he's 6 foot and doesn't have long arms. D-Wade has at least a wingspan of 6'11".