Nah, I doubt it's Saifedean, same with Michael Saylor on Nostr. These accounts rarley publish unique content, only boost and quotes. 
And most important the accounts just stack zaps they never zap themselves. It's obvious, they are just out there to grap zaps. 

Don't follow/zap an impersonator 🤙 

 Nope it really is me. I tweeted my public key on Twitter a while back!

https://twitter.com/saifedean/status/1643183805602189314?t=49IINCQDyWM2cFus4ltQYw&s=19 

 Forgive me! If you're Saifedean you earned everything zap ⚡🫂 Glad to have you on #Nostr

It would be even more trustworthy, if celebrities would use their personal domain as their Nostr-address (Nip-05)  and/or their LN-adress.

Example: @Vitor Pamplona does that nicely with his personal domain, so plebs can be sure to zap him and not one of the many impersonator 🤙 

 🤙 

 LETS GOOOOOO SAIFEDEAN IN THE Mf house!!!!! 

 Are you coming to nostrasia? 

 Unfortunately no 

 Saif, great to see you here. 

 It's Saif. On the other hand he's not really "active" on Nostr. 

 He's a total animal that man , a force of nature , like a Tsunami , he doesnt give a fuck if normies shit gets wrecked in his wake, and all he is doing telling the truth .  

 Life's too short to mince words🤝