The parent said "curing genetic diseases", not "CRISPR".

Health, intelligence and facial symmetry do seem to be linked to the absence of deleterious mutations so yes it may well be that the children of wealthy people benefit, in the farther future. I don't foresee any particular harm, since the standard arguments apply: what starts as luxury eventually becomes accessible to all with the rich having paid the development costs.

Also consider that since the industrial revolution child mortality in the West has declined tremendously (thankfully), so it's possible that our genomes have accumulated mutations presently unknown which will need to be deleted at some point. Better done via gene-editing tech than via the cruelties of natural selection or eugenics.