Quoting: Hitagi_Senpai
It just makes no sense, since he has no NMC atm. So the market for him will be a few teams that can afford him. He wouldn't be worth "nothing" I highly doubt Crosby will ever waive. Even to play in Toronto. And Matthews > Crosby. Regardless of the contract.
This scenario isn't plausible due to the NMC is not existing. If he was put on the market, almost every single contender and say Arizona and Anaheim would be all over Matthews. And the return he'd get would be a insane amount. He's a top 15 player in the NHL.
While the hypothetical scenario you said could exist, parts of it are so highly unlikely. I think he's going to Arizona. Even with his NMC he'd waive for Arizona.
Once the NMC kicks in, Toronto loses control over the asset. Come trade deadline, whether or not Toronto is in the playoffs, Matthews could decide he doesn't want to take on the risk of taking a trade. Or that he only wants to accept a trade if it is to his ideal destination with a massive contract in place. In which case, Toronto is not getting a massive return because that team already knows they can wait until the summer and have a very high chance of signing Matthews.
Crosby may not want to leave Pittsburgh at all, but it's obvious there are major changes coming there. If they decide they need to rebuild, he may want to go to a more competitive situation rather than spend his final few years on a non-playoff team. There is also the post-career aspect to consider. Crosby has been one of the most marketable players in the league. Going to Toronto and possible bringing them a cup (I hope not) would have massive implications for his legacy and however he chooses to market himself in his post playing career. Similar to how Gretzky wanted to go to Toronto or New York.
If the Leafs offer to make Matthews the highest paid player in the league on an 8 year contract with a NMC, front loaded money, and signing bonuses and he turns it down wanting to play out the season, then he is very unlikely to stay. In that scenario, they aren't weighing whether 9 more years of Matthews is worth more than 2 of Crosby, they are weighing whether 1 of Matthews (or whatever trade return they get for him at the draft) is worth more than 2 of Crosby. At that point, age is hardly relevant, unless you think Crosby is going to fall off in 2023.
Both in the room and for their fan base, unless they come back against Florida, they are going to need to do something major. Bringing in the biggest or second biggest name in the league, who has won multiple cups, and is apparently a strong veteran leader - that's a major change. You also have to factor in the cap implications, they save a few million by switching from Matthews to Crosby next year.
This isn't a trade they should make if Matthews is going to stay. That would be idiotic. The idea is, if Matthews has one foot out the door, the opportunity cost would be 1 year of Matthews, 9. In the Leafs unique situation, 2 years of Crosby helps them more than 1 more year of Matthews. If the right futures based deal is on the table for Matthews at the draft, you could make an argument for that instead, but I don't think they are going to want to take a step back and re-tool.
Also add in the fact that if they add Crosby, it likely frees up cap to improve the team elsewhere, and possibly make a move like re-sign O'Reilly.