Discrepancy between IDE0072 and CS8510

[viceroypenguin]

Version Used: Compiler version: '4.12.0-3.24523.4 (f3348c2)'. Language version: latest (13.0).

Steps to Reproduce:

1. Enable EnforceCodeStyleInBuild
2. Set AnalysisLevel to latest-all
3. Use the following code:

#pragma warning disable IDE0008
#pragma warning disable IDE0059

char c = 'x';
bool i = false;

var x = (c, i) switch
{
    ('L', _) => '#',
    ('#', true) => 'L',
    ('#', false) => 'M',
    (var z, _) => z,
};

var y = (c, i) switch
{
    ('L', _) => '#',
    ('#', true) => 'L',
    ('#', false) => 'M',
    (var z, _) => z,
    _ => ' ',
};

Diagnostic Ids: IDE0072 (Populate switch); CS8510 (The pattern is unreachable. It has already been handled by a previous arm of the switch expression or it is impossible to match.)

Expected Behavior:
No diagnostic to be reported on the first switch expression, as it is complete.

Actual Behavior:
IDE0072 is reported on the switch, indicating the analyzer believes that there is a missing branch; however (var z, _) covers all remaining cases.