@FullmetalJunI don't work for Bose but I am not surprised. I known many different Bose products involving QC35, Revolve, Mini 2 and Soundsport. Not a single one of them has been updated in 2020. I don't believe Bose is picking on/singling out the QC35ii. The 700 which is essentially still new, was updated once in May.
My guess is that Covid has slowed down any team development work on all their products and thus I would be pleasantly surprised if there is an update for any of the above in 2020. It is really hard to develop and test something of the complexity of firmware when working out of your house. Firmware is worked on by many - zoom meetings can go only so far. 🙂