It depends on what the team's primary goal is. When do they really think they have the chance to make a run? Does competing next year have greater priority than competing 3 years down the road?
They have said they want to "compete" next year. People seem to think that means taking a run at the World Series. But that could easily be interpreted as, "We don't want to look like fools out there next year." The latter is a very different scenario.
If the Jays really want to take a run in 3 years, then trading Donaldson is the right move, if you get an offer you can't refuse. Namely someone who can help you now plus good prospects. That's not popular with the fans but from an organizational perspective, it's the right move (assuming your run is in a few years, not next year).
The fans want the new GM to prove himself and, ironically, making the right move (trading Donaldson) may be the real litmus test.