Certainly possible but if the odds get really short there might be something to it. Moyes next utd boss went from pretty long odds to 1/4 very quickly last year, well before any thing was announced.
TBF, Moyes to succeed Fergie was an open secret for years before it came to pass.
I doubt he was ever "long odds" to take up the OT post.
As someone else said, a fifty quid bet brings the odds tumbling in these next manager or player's next club markets.
Some bookies actually start the rumours themselves to get the gullible to lump on.