你的“exist to copy”逻辑并不是真正需要的，因为如果文件不存在，get-childitem就不会找到它。
下面的代码将检查文件是否存在于源中而存在于目标中，如果是，则写入到文件已移动的主机：

$source = 'C:\Users\myuser\playground\powershell\Source\'
$destination = 'C:\Users\myuser\playground\powershell\Destination'
$files = Get-ChildItem $source -File | where-object {$_.Length -ne 0}

foreach ($file in $files) {

Move-Item $file.FullName -Destination .\Destination

if (-not(Test-Path $file.FullName) -and (test-path (Join-Path -Path $destination -ChildPath $file.Name))) {
    Write-Host "$($file.name) has moved"
}

}

为什么不直接使用-verbose呢？

Move-Item -Destination (new-item -type directory -force ($SchoolFolder + $newSub)) -force -ea 0 -Verbose

根据您的意见更新。

这样试试...

$source      = 'C:\Users\myuser\playground\powershell\Source\'
$destination = 'C:\Users\myuser\playground\powershell\Destination'

Get-ChildItem $source -File | 
where-object {$PSItem.Length -ne 0} | 
ForEach-Object{
    Move-Item $PSItem.FullName -Destination '.\Destination'

    if (-not(Test-Path $PSItem.FullName) -and (test-path (Join-Path -Path $destination -ChildPath $PSItem.Name))) {
        "$($PSItem.name) has moved"
    }
}

最终脚本：

$StudentName = Tyler
    $RenderFolder = "C:\Users\MyUser\Desktop\Render"
    $MP4existsToCopy = Get-ChildItem $RenderFolder -File | where-object {$_.Length -ne 0}
    $SchoolFolder = "C:\Users\MyUser\Desktop\School Folder\$StudentName\$Month. $MonthWrite\$Day. $DayWrite"
    
    foreach ($file in $MP4existsToCopy) {
    
    Move-Item $file.FullName -Destination (new-item -type directory -force ($SchoolFolder)) # new-item - Serves to create the folder if it does not exist
    
    if (-not(Test-Path $file.FullName) -and (test-path (Join-Path -Path $SchoolFolder -ChildPath $file.Name))) {
        Write-Host "$($file.name) was moved!"
    }