I surfed around and read news that the Westin Chosun hotels in Seoul and Busan will be rebranded to Chosun as part of Shinsegae Group's hotel restructuring. The article states that the Westin name will be dropped:

http://pulsenews.co.kr/view.php?year=2017&no=429826

In past news, another hotel-owning subsidiary under a Korean conglomerate is also making a name change. SK owns what was the W hotel on Walkerhill and will revamp it as Vista Walkerhill hotel. It has been closed likely due to renovation.

Another renovated hotel will be undergoing a brand name change as the former Ritz-Carlton property in Gangnam will switch over to SPG and re-open as a Le Meridien. As a result, Starwood hotels will maintain a luxury presence in South Korea albeit in a smaller footprint.

http://pulsenews.co.kr/view.php?year=2017&no=430157