False positive: let with flow annotation not counted as declaration

[NilSet]

I want to report a bug.
let variable declarations annotated with a flow type are seemingly not tracked as a declaration.

SonarJS version: 3.2

Rule key: S2703 aka VariableDeclarationWithoutVarCheck

Reproducer

let unflowed;
unflowed = true; // ok

let flowed: boolean;
flowed = true; //false positive

Expected behavior
Recognize the annotated let statement as the declaration of flowed instead of assuming the usage of flowed is an implicit global declaration.