What is criticism anyhow? Feels like you could black knight this hard with clever phrasing. “The company does a fabulous job keeping its employees loyal regardless of circumstances!” “Yes they have the best and toughest employment lawyers in the business! They do a great job using all available leverage to force favorable outcomes from their human resources!” “I have no regrets working there. Their exit agreement has really improved my work life balance!” “Management never lets externalities get in the way of maximizing shareholder value!”
If a contract barred me from providing criticism I would not imagine that I could sidestep it by uttering positive criticism unless my counterparty was illiterate and poor at drafting contracts.