Panasonic claim they can't due to a memory issue, e.g. they haven't got enough space to store an extra mode.....there might be some similar limit to how many modes you can have on an LG TV (though givem modern processing power and how little space it would take up I find that explanation bizarre). Maybe they could have you choose to lose 'vivid' mode to get it.
You can just set up an existing mode with the same settings filmmaker mode would have. Not quite as nice as having a button on the remote and auto sensing etc but the same effect.
Looking to get a 65E9 myself this month, but I was hoping to pay 'only' £2k, they have gone back up to £2.5k recently.