Everything you can get in an alternative app store has to be approved by Apple and they only approve stuff they'd allow in their store, making it not an alternative.
To be an alternative to the Apple App Store, it just needs to be able to match the abilities of the Apple App Store. Again, the DMA is not about freedom, but about fairness between app stores on the platform. Apple can define the playing field such as selling notarized apps only, but it must be an level playing field among all app stores.
