Is there no current PowerShell module support for Splunk? I am only finding old articles on this and various sites.
What exactly are you looking at/for? Have you checked Splunkbase (apps.splunk.com)?
What problem are you trying to solve?
10 years ago there was a module called of all things "splunk" that you could use to connect to an instance and pull data out.
The connect cmdlet was called Connect-Splunk and was part of the module set.
Shocking if this vendor decided to abandon Powershell.
Not really. Maintaining anything uses time and effort. Essentially, it costs money. Even if there was a splunk powershell module 10 years ago, since then both splunk api evolved as well as powershell did. And since windows is not really the main operating system of choice for splunk (yes, you can run splunk on windows but it has some limitations and it's usual;y better to just go with linux) there is much more demand for tools for unix-based admins and devs. Simple as that.
On the other hand, you can always run python on windows and use python splunk libs.
Not shocking at all. Businesses have to make decisions about where to focus their efforts and money and it would seem PowerShell did not make the cut. Software on GitHub probably was not official and the employee who built it may have moved on to other things.