How would that be phrased in Spanish? Are you talking about the future tense in constructions like "Será que...?" or "Estará volviendo" to say "he must be returning"?
Yeah, it's very common in news because it's a very concise way to indicate the possibility of doubt because it's just "gossip" (as the title here would have it).
As explained, mood is implied. This is a common pattern in news reports, etc., not quite colloquial