No, it's not despite playing out from the back at all, such a throwaway comment. Their entire football identity is built upon the foundations of playing out from the back. Guardiola did the exact same thing at Barcelona and had one of the greatest club teams in history, then went to Bayern Munich and implemented the same style there.
United brought Andre Onana in specifically for his ability with the ball at his feet, as that was something De Gea wasn't good at and he was let go. Yes, United have been poor so far this season, but that doesn't discount from the style of playing being one that's been the catalyst for some of the best teams in world football for well over a decade.
Again, call it 'fannying about' as much as you want but all it does it show that your views are out of touch with what is and isn't successful in modern football.