This shift in focus towards the US market is part of Ripple's response to the "Trump effect," which is believed to be making crypto more favorable in the US.
South Korean markets tend to prefer XRP over larger assets such as bitcoin and ether, and a volume bump tends to precede price anomalies on local exchanges.
While RLUSD’s price will always be redeemable for $1, some onchain “collectors” are likely bidding to be the first to hold the much-awaited Ripple stablecoin.