Yes both those are examples of “staying in the same isolation (actor)” and therefore no suspensions take place in such calls.
By the “in general” I meant the very general case of two arbitrary contexts, I should have specified more concretely that there exist specific cases where we can know for sure.
Also depending on the default nonisolated async func isolation mode — accepted in [Accepted with modifications and focused re-review] SE-0461: Run nonisolated async functions on the caller's actor by default — calling a nonisolated async function under the caller isolation mode would also not cause suspensions but just keep running on the caller. But that’s dependent on which execution semantics a function has