If he plays 2+ more healthy seasons in the NHL, then yes. If he plays just 1 more healthy season, less likely, especially if he leaves Philly (Philly were an offensive powerhouse last season, and he's unlikely to find a better center than Giroux).
I get that he signed with a hated rival but there is something fundamentally wrong with Penguins fans hating Jaromir Jagr. Part of me hopes that everyone involved lets bygones be bygones and he re-signs in Pittsburgh to finish his career. Of course that will never happen though.
Not in one season, maybe in 2. He played with Giroux and Hartnell most of the season on an offensive minded team and didn't hit 25, he'll be 41/42 years old next season and likely won't be a Flyer. Even if he is, he may not get the minutes he did this season, especially considering how badly he faded.