What I was trying to say is that Wise haven't physically transferred any money to Thailand. Once the money is deposited to their account into the UK, the equivalent amount as already agreed, is paid in Thai Baht from their account in Thailand, to your account in Thailand. The time scales, when that quick, are still impressive though.
It's the same principal as used by Western Union, money gram and countless unofficial, unlicensed similar operations in the UK, used to send money to Countries such as Iran, Iraq, Somalia er al.