To support the OP's stream of logic it; the reversal should not extend to only trade deadline deals but any deal that included player contracts that extended beyond the COVID-19 pause.
Let's face it a team acquiring a player with a 4 years remaining on their contract 3 years ago expected the NHL to play an 82 game season and playoffs in 2019-2020. So in the OP's fairness world that should be reversed as well.
The bottom line, it is a terrible idea. Whatever unexpected undesirable outcome that occurs after a trade is part of the deal.
Let's face it a team acquiring a player with a 4 years remaining on their contract 3 years ago expected the NHL to play an 82 game season and playoffs in 2019-2020. So in the OP's fairness world that should be reversed as well.
The bottom line, it is a terrible idea. Whatever unexpected undesirable outcome that occurs after a trade is part of the deal.