you might ask via Technical ticket , however note that date is just estimated/expected release date as Fortinet does not have fix release dates and so there might be delay in release caused by extended Q&A test, or new issues found during test, or due to new feature getting in and not yet ready as we would like it to present as complete as possible. There is many reasons.
Another approach is to listen to RSS release feed !
Which URL https://pub.kb.fortinet.com/rss/firmware.xml can be found on the bottom of the Firmware Download page on Support portal https://support.fortinet.com/Download/FirmwareImages.aspx
Other RSS feeds, like PSIRT one, can be found https://www.fortinet.com/rss-feeds
Tom xSilver, planet Earth, over and out!