It depends on what kind of third person you're going for.
You have the omniscient narrator, in which the reader is privvy to everyone's thoughts, backstories, actions etc. Changes in scene are not necessarily dependant on the protagonist. For example you have the MC going away on an adventure, but the narrator tells us how his wife got gang-banged by the farmers, blacksmith, butcher, mailman, mayor, and even the horses. This way, the readers know more than the characters themselves.
You have the protagonist centered narrator, in which only the protagonist's thoughts, backstory, and actions are shown/told to the reader. Other characters are shown through interactions with the protagonist only (or mostly). Any change of PoV would be centered in the new character, making the MC a secondary character for the duration of the PoV.
You have the Re-telling narrator, in which future happenings may be told to the reader. For example "At this moment, he knew... he fucked up, because he was going to get stabbed by his mom while showering." And then it happens. This way, the narrator knows what is going to happen, and so do the readers.