If you can get Pettersson to sign that same deal that Larsson got, I don't really have any issues with re-signing Pettersson
Whether you trade him in 2024 or 2028 won't impact his value. His value is like 2 2nds regardless of when you move him, and similar players (guys like Tanev) even bring back that kind of value into their mid 30s.
I don't want to see some asinine 6 or 7 year deal, that would be ridiculous. But a 4 year deal with plans to flip him in year 3 of it? Sure, why not.
Difference between Guentzel and Pettersson is what they'd cost to re-sign. Guentzel's extension locks him in with Tampa Bay for the rest of his career (effectively) with a full NMC, 7 year term and $9 million AAV. Pettersson's deal will not be nearly as restrictive and likely will be trade bait before the end of his deal.
I say this when making it explicit that any sort of major NTC or major term on Pettersson's deal would change my tune on this dramatically.