At this point I think I'd actually prefer the tournament. I just don't think 100 baseball games with no fans and weird locations/formats will be all that fun, especially as teams start to fall out of the races, and I'm sure not planning to hang out in sports bars for the length of a game, even at 50% capacity. Still pretty skeptical they can do the amount of testing and quarantine they want, and playing a longer season means more exposure for everyone (but particularly support staff).
Let the NBA go first - they have far fewer people to manage, especially since MLB teams will need to carry pretty much its entire 40-man roster. Then do something like Passan's idea. If they can start in August instead of October, the timing would be normal, and/or you could extend the play-in rounds.
Oct. 1-20: Every team plays a four-game series against each division opponent with a day off in between. The two best teams from each division advance.
Oct. 22-Oct. 31: The six American League teams that advance congregate at one hub. The six National League teams gather at another. They play each of the other five teams twice in a round-robin format with a collective day off in the middle. The four teams with the best records in each league advance. In the meantime, the nine non-advancing teams from each league meet at a hub and play one game against the rest of the teams there. The winner of that round-robin regains entry into the playoffs. In the case of a tie, hold a winner-advances one-game play-in-to-the-playoff.
Nov. 2: The play-in winner faces the No. 4 seed from the advance round-robin in a one-game wild card. Winner advances to face the No. 1 seed.
Nov. 3-9: Five-game division series with one day off between Games 2 and 3. Winners advance to league championship series.
Nov. 11-19: Seven-game LCS with standard days off. Winners advance to World Series.
Nov. 21-29: Seven-game World Series with standard days off. Sixty days on the dot. Happy Thanksgiving.