Yeah, I would say his potential is in that 2nd tier. Imo, he's an overall stronger player than Fantilli. He doesn't bring Fantilli's size & physicality though.
He's around the same size as Nathan MacKinnon during his draft year, and brings elite speed & hands. He gets comparisons to Toews due to a really high compete level and defensive play. He really attacks/pressures players on the backcheck.
Celebrini will be playing with Lane Hutson at Boston University next season. Toews also played NCAA during his draft year (North Dakota), and was just under a ppg.
We'll what Celebrini does at BU. Hockey East is a tough conference, so he'll be well challenged.