I'll give the policy answer first, but I'll ask my colleague Alain Laurencelle to speak, as well, from the legal side.
The idea would be, as I hear it, that we would have two rules, one for adoptees who are over 18, where they would be subject to criminality or security prohibitions...but not for adoptees under 18. So you're creating two distinctions there. You're creating the obvious age distinction among adoptees, but you're also still creating a distinction between individuals who have been adopted and individuals who are natural-born.
So my previous comment about that going against the purpose of the bill still applies. You would still be saying--and you'd still have to come up with a section 1 defence--that individuals who have been adopted are more likely to be criminals or security threats than individuals who are not adopted, because you're not saying to someone who was born to a Canadian citizen 18 years ago or 20 years ago that their citizenship is subject to a criminal test.
I'm not sure if Alain wants to add anything to that.