It's the most probable TES V since none of TES games were situated there and because bethesda trademarked the name Skyrim shortly after releasing Oblivion in 2006, I agree it's very likely they have changed their minds or even forgotten the thing completely but it is the only speculation we can make that actually has some evidence behind it.
To be honest I wouldnt want to be in Cyrodiil again, not only Cyrodiil anyways.
If it were up to me I'd want the whole of Tamriel in the next game... but we can only dream