Probably, or if not they're simply just projecting their hitting line based on their previous results, where a player's results are influenced by how they're platooned.
For instance, Alvarez is a career 118 wRC+ vs RHP and 68 wRC+ vs LHP. Morales on the other hand is 117 vs RHP and 107 vs LHP, so you don't need to waste a roster spot on a platoon partner nor do you have to worry about taking him out of the game if a lefty specialist comes in.