Hi guys! Long-time lurker here. I have often almost made an account during the past 10 years, but never did. This chapter, however, finally made me take the leap. The reason is this. My interpretation of the Rocks/Locks thing was simply that Garp addressed Hina by her epithet, "Lock" Hina. He was like "Oh it's you, huh… interesting you know about that since you're so young".
I haven't seen the raw to compare the original Japanese, but I think we should consider this possibility. Don't let it kill the Big Mom and Kaidou were once in a crew and its once-legendary captain may be surfacing again-hype, I just don't think that constituted a name-drop.