User not found after removing user from SP groups

First thing I did was list all the SP groups a user was a member of via Powershell by running:

Get-SPOUser -Site https://xxxx.sharepoint.com -LoginName email address removed for privacy reasons | Select-Object -ExpandProperty Groups | FL * 

This spit out a list that included groups and sharing links and look something like:

SharingLinks.xxxxxxxx.OrganizationView.aca4629b-2156-466f-be31-eead2188db4e
SharingLinks.xxxxxxxx.Flexible.630dde56-f7ca-47bd-86bb-c26dbba1a903
SharingLinks.xxxxxxxx.OrganizationView.04dd59e4-7cae-4290-aff0-477af7626f26
Facilities Management Members

  So I ran these commands to define the user and groups:

$user = Get-SPOUser -Site https://xxxx.sharepoint.com -LoginName email address removed for privacy reasons
$userGroups = Get-SPOUser -Site https://xxxx.sharepoint.com -LoginName $userLoginName | Select-Object -ExpandProperty Groups

 And then I ran this command to remove him from the groups:

foreach ($group in $userGroups) {
    Remove-SPOUser -Site https://xxxx.sharepoint.com -LoginName $userLoginName -Group $group.Title
    Write-Host "Removed user $userLoginName from group $($group.Title)"
}

This took a long time and I suspect it removed the user from all the sharing links too.  Now when I run the Get-SPOuser command, I get the error:

Get-SPOUser : User cannot be found.
At line:1 char:1
+ Get-SPOUser -Site https://xxxx.sharepoint.com -LoginName users@co...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Get-SPOUser], ServerException
    + FullyQualifiedErrorId : Microsoft.SharePoint.Client.ServerException,Microsoft.Online.SharePoint.PowerShell.GetSPOUser

So my questions are:

1. why would it remove the user from SP if I am only removing him from SP groups?
2. what would be the behavior of the documents he modified if he is removed from SP?