This is more about paying attention to the context in which the phrase was said. A lot of things get confusing or might mean a total opposite of what you think they do, when the relevant context isn’t taken into the account.

“Private market will regulate itself” isn’t some technical term with a precise meaning that can be misused. It can “regulate itself” by not having any restrictions imposed on it, but i can also be said to “regulate itself” by exploring different solutions to challenges presented by legal requirements with no clear solution path.

However, I see your point here, because most of the time when people just say “private market will regulate itself”, they talk about heavily unregulated market situations.