I'd leave it just as it is. As so many have said, it will be cuddled and drug around the nursery and loved till the last thread gives way. If you were to add more quilting now with the batting being smaller, you'd get tucks and personally, I'd rather have puffy than tucks.
I've learned so much about batting in the last couple of years. I used to always use warm and natural straight from the package but now I preshrink it. Put it in hot water in the washer, let it soak 20-30 minutes, spin out the water and dry in a hot dryer. Warm and natural 100% cotton shrinks 3%. So when I make a full sized quilt that's about 70" x 70", it will become more like 68"x68". To me, that's a lot a shrinkage. I didn't know about the 'bumps toward the backing' either. And, warm and natural is a bugger to hand quilt through. FMQ is okay, though.
I've found that using the Dream battings with 80% cotton, 20% poly works well without preshrinking and hand quilting is easier. I'm not fond of poly but this one seems to stay inside the quilt and not beard through.
I did a summer quilt with a super thin batting that I hand quilted. It turned out very nice.
There's so much to choose from out there..... and I hate to discover what's bad about each one after I've finished quilting. But, that's how I learn I guess.