If they had it before why the hell didn't Lucci use it when he was using finger pistol and hit Luffy like a 100 times in the beginning of the fight? That would have ended the battle pretty damn fast lol
My interpretation of Luffy VS haki is that the attacks do not land on him as if he wasn't made of rubber, but only hurt as if they did. Luffy's skin is just as hard to penetrate with a blunt attack as it's ever been, the haki coating would just sent a jolt of pain through him when the finger pistol lands. But hey, I've been wrong about haki-related stuff before.
–- Update From New Post Merge ---
Hard to say what the go is with Lucci's other card saying he learned during the timeskip. Possibly just something that's come of all the other Cipher Pol agents only having one card for pre- and post-timeskip, possibly not. Is there any other likely interpretation of the text on the CP0 Lucci card, like that he spent two years training it up rather than acquiring it?
I prefer the idea of them having it before. It just works better with the worldbuilding and the number of blunt attacks that caused Luffy real pain. Plus the fact that all haki was still rendered invisibly at that point leaves it perfectly consistent with what was shown.