It’s not a new case at all. Go back and read my first post again, there’s no change in subject.
Stamkos is the second- or third-best Canadian LW (depending what you think of Marchand and Huberdeau) with a specific skillset (RH sniper) that makes him a deadly asset on the PP. He’s not out of place at the international level as a C, especially when you’ve got a glut of elite defensive matchup guys at that position.
Tavares isn’t way off the mark, but he’s neither a top-6 LW nor a top-6 center in this context. Assuming they want guys like Bergeron and Wilson to fill in the bottom-6 (which they almost always do, because they want guys who don’t need to adjust to an unnatural role during a short tournament) then it doesn’t make sense to replace one of them with Tavares.
I can see them adding him as a 13th/14th forward for injury insurance, because he’s in that short list of candidates if a top-6 guy goes down, but as a coach you’re going to have a lot more options to begin the tournament if you start with Stamkos on the active roster and go from there.