Hi @spartatestlabs, @rlegg50, did you ever get the 4.8.4 version of the app?
If you still require it, please contact your Splunk Account team (sales/customer success team) or Splunk Support and reference this Splunk Answer so that they may assist you. Feel free to ask them to reach out to @rkantamaneni_splunk .
Note, Splunk Enterprise 6.x and 7.0.x will be ending their support lifecycle this Fall, so it's encouraged to upgrade Splunk as well as your Windows Infrastructure App & Add-Ons.
No, Splunk Addon For Windows 4.8.4 is no longer available to download. But Windows Addon 5.0.1 and Windows Addon 6.0.0 are both compatible with Windows Server 2008R2 as mentioned in https://docs.splunk.com/Documentation/WindowsAddOn/latest/User/AbouttheSplunkAdd-onforWindows So I don't see any issue in going ahead with the latest Windows Addon. Let me know if you have any concerns.