If it helps any to know, my DD (my first) didn't get nightweaned on purpose, she just started sleeping through the night without a peep, in her own bed, after about 18 months. I weaned her at 2 1/2 years because I was pg and just couldn't handle the sensation, and wanted to resume eating dairy, which she was allergic to. So I don't think nightweaning was the beginning of the end for her.
A friend nightweaned her child as a young toddler also, and that child self-weaned at 5.