If they have the space where this deal won't keep them from retaining other, more important players - and I don't see why it would - its not a bad deal. And I'm not someone who likes Strome.
He's definitely a capable PP player, has the ability to play with top players at ES, can play C and is not a liability in the dot... but there are probably aspects of the centre position where he ranks pretty low league-wide, and he's not a play-driver at 5v5.
It is tough for me to see him as a good player on a good team, but forwards who would be 18+ min guys on pretty much any team in the league get more than $5m. By the time this deal is wrapping up, we'll have a 2028 cap and Strome will just be turning 30. He could improve by then, but even if he doesn't, I can't see that contract being untradeable unless Strome really craters/suffers a significant injury.
For all the talk of the Strome brothers being busts - and, to be clear, I would not want either guy on my team for anywhere near their current salaries - they have both carved out decent careers and will retire with a whole lot of money.