We are looking into a Debian repository based solution instead of Qt Online installer for Debian. We are not planning to bring in Debian host OS support immediately, instead we are investigating supporting Debian packaging and repositories from Qt for delivery and installation and maintenance on Debian based Linuxes (instead or on side of Online Installer). However, host support is not in the initial scope but once the Debian module has been successfully provided, module-dev could be used for Debian host support, however not by TQC.
With the new Debian release glibc is now compatible with OpenSuse so our source binaries should work in both distros, covering the basic needs to run Qt on Debian.
Hence the effort needed by R&D is very low.
To summarise, Patrick Franz from KDE is now doing packaging for Qt6 as Qt6 Debian maintainer so the basic dpkg packages are doen without TQC involvement, Also Qt6 will be part of DEbian next release aroudn 2023.