I would like to check if it's in Splunk's roadmap that the Scheduled PDF report service will be made available on windows platforms as well. If so, when will it likely be?
I assume that you are talking about the app found here: https://splunkbase.splunk.com/app/314/. According to the developer, the app is deprecated because the capability to email PDF reports is now baked into Splunk. I am running Splunk v6.2.3 on a Windows Search Head and I can select "PDF" as an email option for scheduled searches and alerts. So I guess the answer is "now"!
While this doesn't answer your question, if you are a Splunk Enterprise customer, be sure to enter this as an Enhancement Request. See this previous answer: How can I Submit an Enhancement Request
