The Wikipedia article quotes V. D. Zakhmatov to say this kind of attack was never possible in the first place because the control systems were either manual or analog, not digital.
Re:Gas Leak in the Baltic Sea
by joshuajill on Tuesday September 27, 2022 @05:21PM
(#33001285)
He says it wasn't likely because most systems were analogically controlled. Emphasis in most.
> Portions of the operation have been disclosed earlier, including in a 1996 paper in Studies in Intelligence, a CIA journal.