assign-type-mismatch not emitted when assigning a class to an array

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Linux

What is the issue affecting?

Type Checking

Expected Behaviour

---@class a
local a = {}

---@class b
local b = {}

---@type a[]
local c = {
    a,
    b, // assign-type-mismatch emitted here
}
c = "" // assign-type-mismatch emitted here
c = b // assign-type-mismatch emitted here
c = a // assign-type-mismatch emitted here

Actual Behaviour

---@class a
local a = {}

---@class b
local b = {}

---@type a[]
local c = {
    a,
    b, // assign-type-mismatch is correctly emitted here
}
c = "" // assign-type-mismatch is correctly emitted here
c = b // No assign-type-mismatch is emitted here.  I would expect it to be emitted here.
c = a // No assign-type-mismatch is emitted here.  I would expect it to be emitted here.

Reproduction steps

.luarc.json:

{
    "$schema": "https://raw.githubusercontent.com/LuaLS/vscode-lua/master/setting/schema.json",
    "runtime.version": "Lua 5.1"
}

Additional Notes

No response

Log File

No response

Reproduce the report using the supplied .luarc.json and Lua snippet, checking the three assignment cases involving the a[] annotation. Trace the type-checking path responsible for assign-type-mismatch diagnostics and compare class assignments with the already-diagnosed string assignment and array literal element. Done means mismatched class assignments to the array are diagnosed without changing the existing diagnostics.