There are a couple Accord forums where these filters are brought up. From the discussions I have read, a few things seem obvious:
1. The Honda dealers don't seem to know anything about these filters. Either don't know they are there at all, and/or don't recommend any replacement. The parts people deny they exist, and quotes for replacing them are over-exagerated - as if they are tearing down the tranny to replace an internal filter.
2. The users who have replaced these filters find that they are designed a lot like an oil filter, and are subject to getting clogged.
3. The consensus from people who have replaced their filters and inspected the old ones is that yes, they need to be replaced on a regular basis. However, since Honda has not seen fit to specify routine replacement of the item (or even admit they exist), recommendations vary a lot.
I just ordered a filter for my 09 Accord V6. The car has 25k miles on it and for peace of mind I'm replacing this filter.