Phil Spencer, the head of Xbox, has answered the question.
On the Xbox website, he wrote in a post that the stronger Xbox One, dubbed the Project Scorpio, will be revealed in detail at the E3 in June. That means Microsoft will focus a lot on the new console, which seems to be stronger on paper, but in comparison to the game line-up (especially regarding the exclusives), the Scorpio looks currently weaker than the PlayStation 4 Pro.
Spencer also had a quite brave comment, saying that the Project Scorpio was designed to become the best console to play multiplatform titles. We still have to know two things about it: when will it launch, and how much will it cost?