If Luchanko were to stick, it's not going to be due to his offense.
It'll be b/c his IQ, maturity and speed allow him to be effective as a defense first center who can provide a little offense.
It's unlikely, but it's an easier transition than an offense first player who isn't fundamentally sound on defense.
Most top offensive players (unless we're talking Bedard level) are going to struggle to score at the NHL level at 18, and their bad defense will be quickly exposed.
The worry is even if Luchanko is advanced defensively, fear of making mistakes will make him too passive, and if encouraged to take risks, lack of experience will result in too many mistakes, making him risk adverse.