Agreed 100%. Anything is possible. But, referencing Couture, I remember speaking with Logan's father the year after and apparently he slipped more so for two reasons:
1) JT was granted status only a few days before the draft. Other teams at the top of the draft had already worked out deals with players just like Oshawa had with Couture. logan had some friends that would have affected so he didn't want to swoop in a quash a deal and the potential ripple effect it would have caused wasn't something the family was comfortable with.
2) there were a couple teams that he pretty much said no to. With different comp scenario's back then, you couldn't trade the player, you only got the comp pick the following year after round one (21st) so the risks were way too high.
So, Logan would have gone top 3 had they simply just said 'oh well' after JT was granted status and let the chips fall where they may.
Although your point still stands, based on this info, I am not sure Couture was a good example.