I think he should draft BPA. This draft is rated to have big drops after 1, 3, 4, 5, and 9 or so. Better to get a really good player than two good ones. If anything trade up with some seconds.
Bergevin does not seem to get this, though. Age is key as players peak early and often drop off early so the Subban and Sergachev trades suck.
Having players play during the early years of their contracts and saving cap hit is key so the Sergachev trade really multiply horribly sucks much worse than anything else he has done and anything he could do beyond trading a #3 pick for an established and expensive player. Bergevin may have some strengths but he just does not get the key aspects of team building as a GM and I have little hope for him. I fully expect yet more "oh no, why would he do such a thing" moments, and no, I did not get a moment's happiness out of the Subban or Sergachev trades, no surprise at how they turned out. I don't know much but I can sometimes see the obvious.
Not to say you should never trade high picks. If your team is stocked and you have a need for a cup run it can be an option. Where the habs are now it would be a bad and clueless move. The habs are not in a position to have a cup run now. The habs are in a position to tank for another year or two while they rebuild well, everything outside of goal.
What the habs need is a steal, a trade that looks like a relatively even trade that breaks their way. It's not likely, though. Ever since Houle habs GMs have been trying to do fair trades while other GMs only take the one sided ones. How many habs trades have been wins? Petry? Wiz? I had to go back 8 years to find 2.
I expect Bergevin will trade the pick for an old, expensive player some other team is desperately trying to get rid of for good reasons.