Based upon what I have seen in the other thread about this, the 2021 trucks do have a redesigned window but might be leakers right from the start due to missing sealant. I don't think anyone with a 2021 has found cracks in their window frames so if they are sealed right from the factory the issue might be a lot less likely to occur. My advice would be to get a truck if its a good deal but don't take delivery until it has sat in the rain a few days and you can inspect it. FWIW, I had a 2020 and now have a 2021 and neither have leaked.