[HenryFord]

Let me give you an example as to why I think this might be useful:
I recently started watching the series Homeland. I got every episode of the two seasons available and added them to the XBMC library. Now, when opening XBMC, "Recent Episodes" only lists Homeland, but in the morning a few episodes of already tracked shows aired (due to my time zone I say "morning", because they air around 3am in my timezone). Now - I know that Homeland is an unwatched series and I'll catch up with it - but I have to do it later because the episodes are quite long and I don't have so much time. But I still want to be able to select the episodes which _aired_ recently, so that I can quickly select them from the homescreen. Otherwise I now have to go to every entry of the shows that aired and select the desired episode - a procedure which takes, compared to selecting from the widget, a lot of time. For me it makes much more sense to order by the date they were aired than by they date they were added.
This is even more true when you add a new series with a lot of seasons (The Office (US) is an example with 9 seasons and over 200 episodes; I recently added it, never watched it before and I marked every episode of the series as watched just so they would not show up in the widget any longer and I could track my regular shows like normal instead of clutering the widget with every single episode of the new series. That of course complicated my tracking of the series, because I had to remember where I was the last time I watched it (or check trakt for what I watched last))

And because I saw this request by a lot of users, I think there are a lot of users out there who agree with that.
And because of that I think it is valuable to add the option. My changes don't change the default behaviour, they simply give the user the option to change the ordering to their liking - and seeing that this has been requested a few times, I don't see any reason why not to add this.