I don't see it as "burning a year"
There's been a lot of kids who have debuted at 19 over the years. I think the team is good enough that they can be in the hunt for the wildcard and the kids tearing it up in the minors. I feel like if the player is ready for the big leagues, that there isn't much sense in thinking 6 years down the line because who knows what the situation will be then. It's not as if the Jays are the Tampa Bay Rays. Toronto has deep pockets, so if they like what they see they should be able to sign him to an extension. If anything, if the kid is ready and the Jays call him up, it will be a sign of goodwill that could go a long way in future negotiations.
If the Jays were just s*** this year, then I wouldn't see the purpose, but they've looked like a decent team. We can't expect the starters to struggle like they have been. I think they'll straighten it out and the offensive pop that Vladdy offers could really help carry the club. I feel like it's worth a shot.
I would wait till the beginning June to make the call though. See how the kid does for the rest of the month.