Earlier quoted context omitted.
You can install RPMs on Debian but most probably you will run into filesystem-level conflicts with DEB packages. But if you are rebuilding your own Debian-based distro, nothing prevents you from packaging everything into RPMs instead of DEBs and that's see. Not that I see the point of that, though.
Yeah but Debian’s package repository is all deb based. It would be difficult to translate precisely into RPM - they have different tooling and semantics.
The whole point would be to rebuild Debian (or the subset you need) and package everything as RPMs, i. e. do not use apt, dpkg, etc but yum/dnf, rpm, etc.