https://www.cnet.com/news/galaxy-s9-plus-rumor-ces-2018/

According to VentureBeat, the pair of marquee phones is rumored to make an appearance at CES 2018, the huge consumer electronic trade show held annually in Las Vegas. 

Though Samsung is expected to fully introduce the Galaxy S9 and S9 Plus sometime in March 2018 (similar to how it launched the S8 and S8 Plus during a March keynote this year), a cameo at CES in January would push up previews of the devices by two months.