I think there would be variation because I had a sour diesel that selfied and the first seed I grew out was way more dense and smelled like stale BO diesel and rotting cantelope and it's parent smelled like lemon pledge and was more sativa in bud structure.
There is always genetic variation when you propagate by pollination. When you self pollinate (by using colloidal silver to produce pollen from an identical clone) you narrow the range of genetic variation as you are not injecting any new DNA, just shuffling the existing genes.