any in array prevents type checking rest of array

[danielzgtg]

TypeScript Version: 3.9.3

Search Terms: "any array", "any list", "any prevents"

Code

// Works properly
let x: number = 123;
let y: number[] = [
        123,
        x,
        true,
];

// Doesn't work properly
let x: any = 123;
let y: number[] = [
        123,
        x,
        true,
];

Expected behavior: For both code snippets to result in the same compile error.

Actual behavior: The second snippet compiles without any error. This is unsound.

Playground Link: First Second

Related Issues: No

[RyanCavanaugh]

Duplicate #19541