I know someone whose lowest grade was in LRW, and then wrote onto journal. I'd think the only correlation btwn LRW and LR is that SOME people who get As are just really good writers and can write anything, and they may be more likely to write on. Obviously not all good writers get As in LRW though, for whatever reason (bad teacher w/ arbitrary grading, the curve had to push someone down, etc.)
And I agree w/ the above poster - try not to worry about the LR decision. Your worrying won't change the outcome at this point, so you should try to relax. And if you do make it, definitely enjoy the glory while it lasts, b/c learning to cite check and writing your comment SUCK.