Somewhat OT, but this has been great for me. I've been trying to kick twitter, but even deactivating my account didn't completely kill it because I kept going back to some profiles, but with this change it's unusable when logged out. I'm finally free.
HN should implement a rule that makes it mandatory to link twitter threads through one of those services that make them readable. It's quite frankly obnoxious.
The link worked fine for me in Firefox without being signed in. Went straight to the first Tweet, showed another, and gave a link to continue reading the thread.
This is a known "feature" of Twitter. If it assumes the user can be logged in, it will hold the page captive until you sign in. I've had it happen to me, though I'm not sure of the details. Like whether it's being A/B tested or what specifically it's hitting on to require login