It’s accurate. The flame path through threaded joints and/or machined faces of enclosures cools the gases.
For conduit runs it also acts as a relief to reduce pressure piling. This is among the reasons “wrenchtight” and five or more threads engaged is specified in Section 500.8(E). It increases the length of the flame path without actually closing it.
Several major manufacturers have literature and films or videos describing these features. At least one can provide onsite demonstrations.