Rotating the account encryption key should have no affect given that you log-out of all clients as you suggested.
The docs even specify that after rotation, the clients should immediately be logged out, though I would argue that being sure to sign out of all other clients before rotating the encryption key as you specified, would be the best practice to ensure no issues.
The only concern when rotating the account encryption key being specified here
Making changes in a session with a “stale” encryption key will cause data corruption that will make your data unrecoverable.
Should one fail to log out after changing the account encryption key, this could lead to data corruption if they tried to make changes to the vault data with the stale old account encryption key.