Biggio is a perfectly cromulent starting 2B on the Jays this year, he doesn't need a platoon. We don't need all stars at every position, we need good players at some positions, all stars at others.
IF we upgrade 3B, I wouldn't hate Espinal splitting time @ 2B with Biggio (and acting as the supersub for the rest of the IF), but I'm honestly not very worried about Cavan, I expect him to have a solid year.