A wrapped squat is still a squat. Do heavy knee wraps allow you to squat more? Absolutely. But other than the weight being higher, you squat basically the same with or without wraps. So training in wraps will absolutely help your raw squat -- it isn't like the wraps take away all muscle stimulus from the squat.
That being said, I think most lifters hold off on doing wraps until close to a competition or when hitting near max. Wraps are painful and take a lot of work to put on if doing them tight, so it isn't something you do on every squat. Also, I think people over-estimate how much extra weight one can lift with wraps versus without. It varies from one lifter to the next, but I think the average might be around 10%.
Source -- powerlifter of 10+ years who trains both regular and wrapped squats all the time.
That being said, I think most lifters hold off on doing wraps until close to a competition or when hitting near max. Wraps are painful and take a lot of work to put on if doing them tight, so it isn't something you do on every squat. Also, I think people over-estimate how much extra weight one can lift with wraps versus without. It varies from one lifter to the next, but I think the average might be around 10%.
Source -- powerlifter of 10+ years who trains both regular and wrapped squats all the time.