If it is, does it have any new designs? I haven't been able to find out ANYTHING about it other than the prologue that came out months ago.
More like "I can't find any answers on google no matter what I type". I can find plenty of announcements about the series STARTING, but nothing past that.
Perhaps I'm not using the correct terms, but I doubt it, as I've tried the English title, the romanized Japanese title, and the title written in Kanji.
So, I tried searching for "機動戦士ガンダムSEED ASTRAY 天空の皇女" instead of "Princess of the Heavens" or "Shuumatsu no Tenki" and I found references to it in announcements for current issues of Gundam Ace. It looks like it's still being published. However, I can't find any information about what's actually IN the chapters. The series doesn't even have a mention on the Japanese Gundam wiki. It also doesn't have an entry on the english Gundam Wiki. It's listed on MAHQ, but it's just a placeholder link. As a result, I can't say whether it's had any variant MS so far.
Image searches on Google.co.Jp only turn up a few images from the prologue.
Also, I found chapter 1 on comicswalker,