I know we have all been wondering when the OP accessories will be released, I noticed that heliguy.com have updated their description for the expansion kit, mount, wireless module and controller wheel to include an expected stock date of the 31st January 2019, I'm assuming they have had information from DJI, as previously they didn't list a date.

I really hope its not that long!!
Come on DJI!!!

Notice that the leaked information didn’t come from DJI.

I emailed Heliguy about getting Pgytech filters and I've also got a pre-order of the expansion kit so asked if they had an ETA. They didn't have any shipping details from DJI (as of Mon 17th) but were expecting them to be early-mid January.

Hello and good day. Thank you for the inquiry and with the information given today. As of the moment we do not have an information when will the said official DJI Osmo Pocket accessories be available in the market. For the latest news and update on the DJI Osmo Pocket and it's accessories. Please visit our official website at www.dji.com for details. Thank you for your support.

DJI has the expansion kit for sale as of yesterday.  I ordered mine and it has shipped already.