Question: When does Apple expect to implement fast roaming technologies for Wi-Fi (802.11k and 802.11r) into macOS?
Answer: The engineers who can answer this are unfortunately not at WWDC. File Radar with details on what you want information on.
Question: There are CoreWLAN bugs that cause the OS to report incorrect information on neighboring Wi-Fi networks. What's being done to fix this?
Answer: The engineers who can answer this are unfortunately not at WWDC. File Radar with details on what you want information on.
Question: Will macOS Catalina and/or iOS 13 have 802.11ax/WiFi 6 support?
Answer: No. File Radar for requested functionality.