Wasn't all the data being exfiltrated by the SolarWinds hack encoded into the copious amount of (seemingly-)random garbage emitted by .NET Framework? Pretty sure C# is typed.
The title is a bit clickbait, as the article isn't saying that statically typed languages don't leak data, they are instead showing a hypothetical language which has a special type checker where types also encode privacy levels and the type checker asserts at compile time that no variable of a higher privacy type is assigned to a variable of a lower privacy type (amongst other things).
The article is really talking about research advancement in information flow control checks at compile time using advanced type systems, and no real language.
That is a different notion of typing. The type systems you are referring to (which is how they are commonly understood) classify data according to the operations they support. In this post, types classify privacy. These two notions are orthogonal and can be combined if needed. There are many many more notions of typing out there achieving wildly different goals.
