1. Moroder is definitely a trendsetter and a game changer, but hardly a shapeshifter - as many have already said. So, shapeshifter reference is pro- Madonna.
2. Moroder's album is 6 months away and is still in the works, so it would be strange if Billboard teased the first single so early. According to Billboard, the artist behind the snippet will be revealed pretty soon, meaning that the song in question will be released in a coming weeks, at latest. So, one more reason to hope it's Madonna.
3. "Back in vogue", unless unintentionally used (and we are reading too much into it), definitely is a M related reference. Question for English native speakers: How often "in vogue" phrase is used nowadays?
4. The snippet does really sound like something Moroder would make, especially given his recent involvement with Daft Punk's album- and the article is referencing Daft Punk. Plus, Daft Punk is confirmed as one of the features of Moroder's upcoming album. On top of all of this, the snippet doesn't really sound like something Madonna's confirmed producers would come up with. But, on the other hand, even if the snippet reminds me of Moroder style, I can hear (or it's my wishful thinking) some production ticks that Avicii uses in his productions, like 70s disco style produced by Avicii, to be more precise.
In addition to all of this: It was rumored that Madonna was looking for an Italo Disco style and I'm sure some members remember that, as it was also posted here. This snippet has that Italo Disco flavor, and coincidence or not, Giorgio Moroder was one of the producers that established Italo Disco.
And last, coincidence or not, the first rumored producer on Madonna's album was non other than Moroder himself. It was the summer of 2013. I don't think they did anything together, but who knows? Here's the link:
http://jasontellsitlikeitis.com/2013...s-due-in-2014/
So... my point is that even if all this Madonna - Moroder - Italo Disco - Duft Punk - Billboard snippet connections are nothing but pure coincidence, it's way too much of a coincidence.
I want to believe this snippet is Madonna.