I suspect that cham claws work a bit like bird of prey talons, in some respects (bird talons obviously grow much faster!). If you have a captive hawk that was kept on incorrect footing, it is likely to end up with blunted talons which makes it hard for them to perch properly, hunt, etc. If you take that blunted hawk and put them on proper footing, the talons generally will not re-sharpen themselves. Instead, we have to manually sharpen them like a kitchen knife before releasing them into a more appropriate enclosure, where they will be able to maintain their sharpness on their own (mostly). Improper wear patterns can definitely perpetuate themselves!
Now, I'm not saying every one go sharpen your cham's nails, but I can definitely see how if a cham is producing only a certain amount of keratin per month and is wearing that keratin away improperly due to a modified grip, it could be slow-going to fix the problem. Or, if the nail bed is injured, scarred, infected, etc, the nail is not very likely to grow back.