She’s been ill, remember? It could have changed her voice, or they may have had to use studio trickery. Her voice does sound a bit different on this, it seems it’s mostly sung in head voice, but it’s definitely her as her tone is unmistakable.
I saw the trailer at the cinema and, yes, it looks TERRIBLE, but what annoyed me most is Celine half-arsedly singing that line at the end of it somehow made Priyanka believe it was the real Celine Dion.
I will obviously NEVER WATCH this shit but the trailer made me GUFFAW loudly in the cinema and it makes my heart WARM to know that it's not just inside the Moopy microcosm that people can detect she is BATSHIT INSANE and ask her to do stuff like this.