This change was brought about by the ICC mid-2020. It raised quite a few eyebrows, especially within the Top3, as the qualification criteria for the WTC Final was based on the 'percentage of winning' rather than 'total points won'
In all fairness, the PCT system gives a fair chance to the countries that do not play much cricket. In the case of Sri Lanka, Pakistan, West Indies, they now have a decent chance of making it to the WTC Final by winning everything/bulk of what the play. For the likes of the Top3, this is an obvious disadvantage cause they cannot maximize the winning percentage. The more matches they play, the base increases, thereby making it difficult for them to qualify, in case they lose/ draw a few games.
The ICC needs to give its blessings to any proposed tournament. Considering that India, Australia and England are calling the shots in world cricket, it wouldn't surprise me if the ICC green lights this.