When PI AF Client is installed, it includes a program called "PI System Explorer (Legacy 32-bit)". Please remove this from PI AF Client.
The continued support of 32-bit PI AF SDK makes sense, since 3rd-party programs may still depend on the 32-bit version. Also, because the 32-bit version of Microsoft Office was the recommended and default version until recently, many users are still using 32-bit Office and therefore 32-bit PI DataLink and 32-bit PI AF SDK.
PI System Explorer is in a different boat because no other programs depend on it. As long as a 64-bit operating system is being used, the 32-bit version of PI System Explorer will never be needed. Because PI Server has been 64-bit only for a while now, most businesses that use or will use PI are already running 64-bit operating systems on their servers, and so 32-bit PI System Explorer will never be needed on them. Also, most businesses replace their workers' computers every few years, and new computers have all been 64-bit for the past while. If anyone is running 32-bit Windows on a modern computer, it is probably a mistake—one that should be corrected and not accommodated.
There is not much reason to keep 32-bit PI System Explorer around for the clients either. Please remove 32-bit PI System Explorer from PI AF Client. This will reduce the size of the many install kits that contain PI AF Client, reduce the download and installation time, reduce the network traffic, reduce wear on the disk, reduce energy consumption, etc.