As of my last knowledge update in September 2021, I do not have specific information on any recent changes to Red Hat's source code policies and their direct impact on Plesk.

However, Red Hat is known for its commitment to open-source principles, including providing access to source code for many of its projects. Plesk, on the other hand, is a separate commercial product developed by a different company.

If there have been recent changes in Red Hat's source code policies, it would be important to review the specific details from official and up-to-date sources. These changes may potentially impact any software or services that depend on Red Hat's ecosystem, including but not limited to Plesk.

To get the most accurate and current information, I recommend checking the official announcements from Red Hat, as well as any updates or statements from the Plesk team regarding their compatibility with the latest changes in Red Hat's policies. Additionally, reaching out to Red Hat and Plesk support channels can provide specific guidance on any potential impacts or necessary actions.