Dorothy, to answer your question, ANY version of PSP will be able to use your supplies from the previous versions. Even files that are named differently (like .jbr for JASC brushes) would be read and used in more recent versions.
For additional information, the reason an older version might not always read newer supplies is that the features might have differed. For example, in PSP9, the maximum brush size was 500 pixels. In PSP2020, the maximum size is 3000 pixels. So if you try to load a 3000-pixel brush in PSP9, it won’t be able to handle it. But if you load a 500-pixel brush into PSP2020, it would be no problem.