The effect to EA/Bioware's bottom line only applies if the player is a subscriber. With the hybrid model the length of time someone spends playing a character and not paying a subscription also has a minor impact on the bottom line.
Ideally what you want to achieve is a sense that time invested in any character you play is not wasted time. I would imagine the potential for a preferred/f2p player to use the AC swap function to remain playing their character is higher than them going back to level one and levelling up an alt.
I'm just curious, but if the player is F2P or preferred and NOT paying a subscription, what difference does it make how long they play if they are NOT paying the subscription?
Even if they offer class changes on the CM, the revenue that they would receive from a F2P or preferred who wishes to change their class would NOT be equal to the loss of recurring revenue from a single subscription.