A new dated revision of PDF 2.0 will soon be published and comes with a whole series of related standards.
PDF/A-4 introduces various changes in features and structure of conformance levels. Also new are PDF/X-6, PDF/VT-3 and PDF/R. In addition ISO used the opportunity to harmonize all these standards so that it will be more straightforward for a PDF to comply with more than just one standard.
Slides download: https://pdfa.org/wp-content/uploads/2020/06/Webinar_Slides_DietrichVonSeggern.pdf