If a validator that is being delegated to comes out of your selection criteria but is still a performing validator, the unstake will be realized over a few epochs, without going above the 10% limit per epoch. Finally, if all validators are respecting your selection criteria, the bot will slowly reallocate all your SOL towards an "ideal stake" state where the validators in the selection gets stake while maximizing staking rewards. The "ideal stake" for each validator is weighted by the final score of the validator for the epoch.