Last week, Asus sent out the Android 10 beta update to last year's Zenfone 5Z. Asus's current flagship, the Zenfone 6, however, is now receiving the stable Android 10 update, with users in the US confirming receipt of the OTA.
https://www.notebookcheck.net/The-Asus-Zenfone-6-is-now-receiving-the-Android-10-update.441138.0.html