It depends. The 2022 iPad Pro 12.9 6th generation and iPad Pro 11 4th generation come in the same sizes as the Pro 2021. However, despite the screen sizes being the same, there are some differences. The 2022 iPad Pros are very slightly thicker than their predecessors, which means they may need a dedicated case when it comes to products that have a very snug fit.
With sleeves, there should be no problem, and some iPad Pro 2021 cases are also being advertised as suitable for the new iPads. To be sure, only buy a case that specifically says that it is suitable for your iPad.