No. Having raised fry both artificially and parent raised to adult and bred these adults I can say I have never noticed any difference. There are pros and cons to each.Artificially raised fry are initially a little more difficult as its easy to mess them up at a critical development point. Parent raised fry initially can grow faster because they have access to 24 hour feeding...but artificially raised fry that are raised properly can do just as well there. Parent raised fry may also benefit from antibodies found in the parents slime... the flipside is they also are infected by whatever pathogens the parents have such as flukes and bacterias...where as artificial raised fry don't have to deal with that so all resources go to growing. Its also possible to raise fish that are pathogen free as far as parasites.
Another benefit to artificial is you can raise far more fry... a good pair will lay eggs every couple of weeks. At one point I raised 3 batches of fry from the same pair in the time a single batch is raised by the parent. Jack Wattley bred thousands and thousand of fry commercially this way. Our own member Cliff has bred many artificially as well.
Some have raised concerns that artificially raised discus fry will be poor parents. This is also the case in other species of fish. I do not believe that is true. ...Biologically speaking...it would take generations of doing this to affect something as hardwired as parenting instincts. Discus raised artificially grow up the same as parent raised and pair up and raise fry the same.
So why parent raise fry? There are few things in fish keeping more beautiful than watching a pair of discus interact with and raise their fry.Most hobbyist will never forget the experience. I think its probably something everyone that keeps discus hopes for at some point.
Al