Facebook changed its policy on cryptocurrency and blockchain ads; now you can advertise without prior approval.
Facebook banned crypto ads because of fraudulent activities which was increased in 2017. After Facebook, Google will join this ad ban in March 2018.
Facebook, began issuing pre-approved ads about a year ago (June 2018). And then Google was only allowed to advertise on US and Japan (on the terms of the license).
Facebook's removal of advertising bans and the progress of creating its own crypto money is likely to bring volume to the market.
The situation has not changed for ICO ads.They are still covered by the ban.