Apple faces choices. They could try to restrict sideloading further, but that means fighting against a tide of users who simply want to run software they or their friends created.
History suggests this is the likely path. Most people will accept the phone, ipads and computers as they are. Like IndieWeb there is a population of people going against that current, but not a tide. Unless e.g. interoperability reqs from DSA, DMA force the issue. Sideloading is actually installing.