I've always felt that Senyshyn would've been an okay bottom-six NHL forward if he hadn't been weighed down by the circumstances of his draft position. It may be too late for him to develop, but I think he could contribute with regular playing time on the 4th line on a new team.
He's not untalented, but he's become the poster child for bad draft picks because Sweeney reached for him about 2 rounds too soon while two blue chip forward prospects in Barzal and Connor were sitting there (along with Chabot). So he was thrown into a situation where there was a lot of pressure and scrutiny on him, Boston fans weren't unwelcoming but the mention of his name is basically always followed with "we could've had Barzal...", and honestly the organization never gave him a chance to play regularly in the NHL. His AHL numbers are enough to warrant more than 14 career games, but they wouldn't call him up.
I wish him well in Ottawa, just as long as he's not facing the Bruins.