It still looks more like a warning shot towards exchanges to keep their paperwork in order though, so a full on ban on cryptocurrencies is not in yet.
I would not buy into South Korea banning bitcoin as the cause cause of drop in price. Also we need to check credibility of the source about this. If I remember correctly this South Korea and bitcoin topic came up somewhere in December last year as well and as said to be a cause of the drop from 5k USD to 3k USD in bitcoint price.
For now I will just consider this as a piece of FUD or rehashed (?) old news. In my opinion the price is dropping because of altcoins being bought.
It's current news, but arguably it's more a question of regulation, rather than banning:
https://www.reuters.com/article/uk-southkorea-bitcoin/south-korea-plans-to-ban-cryptocurrency-trading-rattles-market-idUSKBN1F002A
Whether it's the cause of the current drop is speculative, of course, as given the current market situation a further drop in BTC price was not unexpected. The drop in BTC precedes the current rise of alt coins though, so the drop seems to be the cause of the rise and not the other way round.