If the real Satoshi came back now, he

1. can't buy a domain to host a website

2. won't be able to use his Bitcoin as the entire world is tracking

3. Even if he used a mixer he won't be able to offramp anonymously

4. Can't really start a discussion with people like the ones he emailed back in the days. emails are just not as open to the public

5. Even if he emailed, no one would take him seriously

6. Proton mail does not accept bitcoin to use a secure email

But he can sign up to Nostr.