That would actually be a good idea. With people growing up and learning on their own, you don’t have a fully controlled system. The world inside the Matrix will be evolving and from time to time there will be some glitch somewhere. If you have a base of defined childhoods, then only physical differences between bodies and random occurences inside are uncontrolled

If I were to construct the Matrix, I would go after cloning (fewer biological lottery) and predefined lifepaths to keep everything nice and stable