Some more clarity
From the post that's linked haflway through the article:
>Clients with other encryption implementations (including Hydrogen, ElementX, Nheko, FluffyChat, Syphon, Timmy, Gomuks and Pantalaimon) are not affected; this is not a protocol bug.
>Meanwhile, we are taking extreme measures to avoid future E2EE vulnerabilities. You will notice that matrix-rust-sdk, hydrogen-sdk and other 2nd and 3rd generation SDKs were not affected by the bugs at the root cause of the critical issues here. This is precisely why we have been working on replacing the first generation SDKs with a clean, carefully written Rust implementation in the form of matrix-rust-sdk, complete with an ongoing independent public audit.
Just think it's worth pointing out clearly as the article mixes past problems and comments from the researchers in such a way that it seems to imply that the protocol itself is to blame rather than the implementation in these older libraries used by some of the clients.