While Win7 MCE (WMC) was free, it was created by a multi-billion dollar company, and was never for profit. So they had some influence in getting things working properly, best in the USA, but also most the rest of the world.
JRiver MC is a paid product, but the team that create a maintain it is quite small, and they have about zero influence in the TV world, really. So there is going to be a bit of faffing around to get EPG Data into the MC TV Guide, unfortunately.
I still use "EPG Collector" because it works well for me, not only collecting EPG data, but enhancing it with metadata from TheTVDB before it is imported into MC.
JRiver have only recently added DVB-T EPG EIT data collection to the core software. Prior to that only the American ATSC data could be collected OTA, or an integrated or non-integrated third party application needed to be used to create an XMLTV file which was then imported into MC.
So, yes, you should be able to get EPG data OTA from the EIT data stream into MC with the core product. The current public release of the software, MC22.0.41, has the functionality in it, and it should work okay.
As I am not using it now, you may need to wait for one of our other Australians to turn up and help you. Jmone and Astromo have both been testing and using the new functionality. Unfortunately most of the discussion about it isn't available on a public forum yet. So perhaps your thread can be the one to clarify any issues.