Is ADL a Form of Counterparty Risk?

Yes, Auto-Deleveraging (ADL) is a form of counterparty risk, specifically the risk that the exchange's inability to manage a bankrupt account's loss will negatively impact a profitable trader. Counterparty risk is the risk that the other party to a financial transaction will default.

In this case, the profitable trader's counterparty (the bankrupt trader) defaults, and the exchange, as the intermediary, uses ADL to resolve the loss, which is a risk imposed on the profitable trader.