To add to my previous post, Gudbranson is probably available but they obviously weren't scouting him...
My guesses
BUF: Reinhart, Kane, Girgensons (seems like a Benning target)
DET: Athanasiou, maybe Tatar, maybe Frk
OTT: Dzingel, Pageau, maybe Ceci (rumored to be available, also set to get raise). A lot of their forwards have some form of NTC, but Pageau/Dzingel don't and they're being paid more next year.
CBJ: Milano, maybe Murray, maybe Calvert, maybe Motte
NJD: Maybe Zacha, maybe Santini, though it could just be a depth forward swap for someone like Noesen or Stafford
MTL: Not a clue. I could see them bring interested in a younger d-man since they moved Sergachev, but I don't know if they'd move Galchenyuk for Hutton(+).