I haven't given extending the auto-delete much thought, so I'm not endorsing it. But, extending it would only benefit the casual player. If someone is trying to build a suite of hero chars so they can decide which to play for tactical advantage, they sure as hell aren't going to let any auto-delete. They are implementing a plan and you'd have to be brain-dead to not log-in once a month with each.

On the other hand, someone who let's their char auto may have several chars but is not running some strategy and life got in the way of CF. It does create a high bar for someone who can't play often to come back.

Let me add, there have been periods of time when CF took a back burner and I had my char(s) auto by accident. But, when I got the CF bug again, I was willing to start over. But, I could see someone else deciding it's not worth the re-investment if they're not as motivated.

Don't make the decision to return to the fields one bit less appealing than it has to be.