Bug, I'm not sure if drinking cough syrup at noon is a good idea or not, but I'll give your question a stab.
Why would that be necessary? What if your parents have died and graduated to a higher plane and their souls are no longer stirring along the same astral plane as you? My answer to your question is they do not NEED to come into contact with your "new" incarnation, though it could be quite likely that immediately after death, when your soul is adjusting to the new realm, your soul could be clinging to loving earthly reminders (your family) before progressing on its journey. If anything, the inverse of your statement may be true. For closure, your soul in its new incarnation may need to come into contact with the aura/soul of your parents to settle itself before progressing.
I may need to smoke a joint before discussing things like this. Unfortunately, I'd be worthless at class tonight if I did so.
Oh yeah, I don't believe in reincarnation, have no idea why I was asked this question, and am generally confused. That, and I have little to no idea of what I was just talking about. It was pure gibberish. Hope it helped.