are their plans when they were going to have positive tests?

It seems the plans should have been evident from the beginning. Something like, quarantine the team until we get coaches and 30/28/26 players with two negative tests 24 hours apart. At that point, the team will resume and will attempt to make up as many games as possible, with the playoffs ultimately decided by win percentage. Instead, it appears he just postpones their season indefinitely. That gives off the appearance he didn't expect to have any positive tests. However, when Juan Soto tested positive right before the season started, hadn't he spent all of summer camp with his teammates and coaches? Why were the Nats allowed to play in their opener? The Marlins went out for a night in Atlanta and apparently contracted it there, so it makes sense to pull their whole team until they find out who doesn't have it. But, the plan likely should have been if you test positive, you're out and your team will continue to play.

This does not surprise me that Manfred seems out of his depth, again. If I were a player, and I knew this was MLB's "plan", I would have likely opted out too. As things appear, there's little chance they actually complete a season.