I don't think he's ever played for the national basketball team, despite numerous opportunities. But now when they go to the Olympics he'll join them?
He has played with Canada several times -- last time being summer of 2021 when he was one of the few NBA players that tried to lead Canada to qualify later that summer for the 2021 Olympics. He actually played great that year for Canada.
He also played with Canada a number of times up to and before 2016 I think (don't have the exact year, maybe it was 15 or 17) at both the senior and junior levels. He had issues with coaching / and or administration and left the program for a number of years.
Canada Basketball asked players to make a 3 year commitment to the program last summer (for 2022, 2023, 2024). As Wiggins had just reached the NBA final he felt he was unable to commit for the full period. He also missed most of the 2023 NBA season for personal issues, so understandable why he could not make this summer.
He has played a fair bit with Basketball Canada over the years, so i think he should be allowed back for 2024 if he chooses to.
For players that have never given their time to Basketball Canada, I don't think the same leeway should be given.