Debian moves far too slowly for that to have been a viable approach. Had that been attempted, we'd be sitting here a year plus later asking why Debian still doesn't support the Pinephone. (notice that it still doesn't!) This way, we have Pinephone support today (pretty much since weeks after it was released) and the majority of the work can be upstreamed so that hopefully by the time Debian 12 rolls around it will be an officially supported device.