Where DSA is really a threat is in its use of App Stores as choke points. However that's a pre-existing threat that should be eliminated anyway.
Discussion
Typical EU propaganda move: introduce an onerous law that instantly kills any small business subjected to it, but then pretend it's fine because it's less work for these (now dead) companies than a theoretical situation where all 27 member status had introduced something similar on their own.
Execpt that's not how it works: individual countries stupid laws will see business leave to a competing country. The EU has much more monopoly power since leaving the EU has higher switching cost.
If you impose a million obligations, then the fact that the "majority" doesn't apply to small businesses is exactly zero comfort. And can change once the frog has a boiled a bit.
"For rogue platforms refusing to comply with important obligations and thereby endangering people's life and safety, it will be possible as a last resort to ask a court for a temporary suspension of their service, after involving all relevant parties."
So basically a scenario where all EU internet providers, app stores, banks, etc are forced to block Nostr by any technical means available. If only a single user makes a death threat.
Likely scenario? Probably not. But the authoritarian tone has been set.