Good to know. I have an inkling that this probably slipped under the radar when the SurfApp team were looking at branding and trademarks. Despite the fact that Suckless projects tend to have a somewhat popular following in the *nix community, it’s probably pretty obscure anywhere else.
I can confirm that the email is only for sending out an invite, for downloading the beta version. You just use your existing MastoAPI-enabled Fediverse account.