Yes of course, remember that this is not replacing Windows 10. Is like a separate product, so there will be Windows 10 (for gamers, developers in PC and Notebooks) and Windows 10X (for tablets and low-end notebooks, like to fight with Chrome OS, Android and the like).
In my country is cheapest to buy a PC than a Notebook, and PC are more powerfull to work developing.
So I never will buy a Windows 10 X to work, I think Windows 10 X will not have Visual Studio (at least in the first years). So you will still need Windows 10 to develop the applications for Windows 10 X.
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Offtopic:
Or if the trend goes all web, the apps will be done in the browser, they're already working on an IDE for GitHub (is their same IDE Visual Studio Online that failed).
I know some other web IDE's like this one (stackblitz.com). This can deploy to Firebase in one click, so no need to have a PC to develop.