Same reaction of mine as well. I mean, how do you even fck up this way? ... I dont know why, but, this is giving me vibe-coded vibes.

Developer might have prompted to include some signature (definitely they didn't use this word, or else AI would not have messed this way) to verify the webhooks as being coming from legitimate source, and AI probably went ahead with the secret key itself :)

Powershell Script to get all webhooks that have actually run (we can't filter by date; but this may wipe out a significant number):

    # Authenticate via `gh auth login -s admin:enterprise` before running this script
    # Save this script as c:\\temp\GHWebookAudit.ps1; then navigate to c:\\temp\ and invoke via `.\GHWebookAudit.ps1 -Orgs @("MyExampleOrg", "MyOtherExampleOrg") -InformationAction Continue`
    [CmdletBinding()]
    Param (
        [Parameter(Mandatory)]
        [string[]]$Orgs
    )

    $results = foreach ($org in $Orgs) {
        Write-Information "Fetching ALL repositories for org [$org]..."
        
        # gh api --paginate fetches every page and outputs a stream of JSON arrays
        # We use -Raw to ensure we capture the full stream before converting
        $reposJson = gh api --paginate "orgs/$org/repos?per_page=1000"
        
        # ConvertFrom-Json can handle multiple JSON arrays in the stream
        $repos = $reposJson | ConvertFrom-Json

        # Sometimes the pagination returns a single array or a list of arrays; 
        # Ensure we are iterating over the objects themselves.
        $repoList = if ($repos.GetType().IsArray -and $repos[0].GetType().IsArray) { 
            $repos | ForEach-Object { $_ } 
        } else { 
            $repos 
        }

        Write-Information "Found $($repoList.Count) repositories. Starting audit..." 

        foreach ($repoObj in $repoList) {
            $repoName = $repoObj.name
            $fullRepo = "$org/$repoName"
            Write-Information "Checking: $fullRepo"

            # Get all hooks for the repository
            $hooksJson = gh api "repos/$fullRepo/hooks" 2>$null
            if (-not $hooksJson) { continue }
            
            $hooks = $hooksJson | ConvertFrom-Json

            foreach ($hook in $hooks) {
                $hookId = $hook.id
                $hookUrl = $hook.config.url

                # Get the most recent delivery... we could pontentially check for activity between the impacted dates, but that would need additional filters/commplexity; for now keeping it relatively simple
                # correction: this only goes back 3 days; so doesn't work... https://docs.github.com/en/webhooks/testing-and-troubleshooting-webhooks/viewing-webhook-deliveries
                # # $deliveriesJson = gh api "repos/$fullRepo/hooks/$hookId/deliveries" --limit 1 2>$null
                # instead use th eexisting hook response's last response status just to say if it has run; though that doesn't say when

                # Extract last response details
                $lastStatus = $hook.last_response.status
                $lastCode   = $hook.last_response.code
                $hasEverRun = ($lastStatus -eq 'active')  # active vs unused

                [PSCustomObject]@{
                    Organization = $org
                    Repository   = $repoName
                    HookID       = $hookId
                    Active       = $hook.active
                    URL          = $hookUrl
                    HasEverRun   = $hasEverRun
                    LastStatus   = $lastStatus
                    LastHTTPCode = $lastCode
                    UpdatedAt    = $hook.updated_at
                }
            }
        }
    }

    # Final Output
    if ($results.Count) {
        $results | Export-Csv -Path "./Full_Webhook_Audit_Report.csv" -NoTypeInformation
        Write-Information "Audit complete! $($results.Count) hooks found. Results saved to Full_Webhook_Audit_Report.csv"
    } else {
        Write-Information "No webhooks found across the organizations."
    }

yeah, I was wondering the same.. kinda big deal that they first of all had the issue and second, that they fixed it in January and only now message about it