There are tons of other websites you can host a crypto script. If Twitter really wants to keep users safe, they should implement a mandatory warning (I've seen this being referred as a "cushioning" page) instead of having a questionable blacklist.
Except they will now use github pages; and if they block all github pages (github.io) they will use codepen or repl.it or tumblr (custom templates), and so on until thousands of page are blocked.
Sounds somewhat like a "Win" to me. Twitter will die in doing so, I don't see anything getting lost there anymore.
So is Net Neutrality. Ensures that random sites (new sites) doesn't distract you.