From the Microsoft website: (I only just noticed this, guess it pays to read descriptions)
Age of Empires, the pivotal RTS that launched a 20-year legacy returns in definitive form for Windows 10 PCs. Bringing together all of the officially released content with modernized gameplay, all-new visuals and a host of other new features, Age of Empires: Definitive Edition is the complete RTS package. Engage in over 40 hours of updated campaign content with new narration and pacing, jump online in up to 8-player battles with new competitive features and modes, experience 4K HD visuals with overhauled animations, get creative with the scenario builder and share your creations with easy mod support. There’s never been a better time to jump in to Age of Empires. Welcome back to history.
I guess at least we will be able to share campaigns easily. New modes? Can we read too far into this?