He's 27th in minutes per game (down from top 3 each of the past 3 years, thankfully), with 23:41, in the entire league this season, what pair he plays on doesn't mean much. Sergachev plays on the 2nd pair, he's still top 40 in the league in minutes per game. Raddysh is playing on the top pair and is playing 18/19 minutes per game outside the top 150, etc. Chara was nominated for a Norris with the Sens while playing on the 2nd pairing.
Sanderson should be soon to pass him with 23:22 per game, but Chabot will still be played as a minute munching top pair guy, regardless of which pair he's on. He's not going to drop below ~23 mins per game anytime soon, no matter what team he's on
There are probably 20+ guys on the top pairs of the league playing <21 minutes a night
Sanderson should be getting ~24/25 minutes, Chabot ~22/23 per game, which is still easily top minutes among all D in the league.
The guys on the 2nd pair are seeing ~16-19 minutes per game, Chabot shouldn't be compared to them, unless he sees his icetime cut by 5+ minutes per game.