This article that I posted previously about their journey talks about 'June' as the timeframe.
"The attack boat will arrive in Canada by June, coinciding with Ottawa’s expected decision on the winner of the patrol submarine program. After activities with the Royal Canadian Navy,
Dosan Ahn Chang-ho is slated to join Rim of the Pacific 2026 naval drills around Hawaii on its return voyage home."
But, related to this timeframe, I had previously asked the question on people's thoughts on when the timing of the announcement would occur - before, during or after the G7 meeting in mid June in France. South Korea has been formerly invited by France to attend. A number of others have said (and I agree with their rational), that the announcement would most likely not occur until after the G7 meeting so as to not create bad blood between us and the Germans/Norwegians if we don't select their boat.