Sounds like Soucy is motivated by the opportunity to play top 4 minutes. He was behind Dunn and Oleksiak on the left side, so it’s possible he has untapped upside.
He’ll either play with Huggy, who has partnered well with every defensive d partner so far (Tanev, Schenn, Juulsen), or Hronek, who’s also paired well with defensive minded partners and will be playing for his next contract.