According to Windows Central, reliable sources say that Microsoft is working on a new Windows 10 app storefront to replace the current, much-disliked Windows Store. The aim, they say, is to "introduce a modern and fluid user interface, as well as bring changes to the policies that govern what kind of apps can be submitted to the store by developers".
One of the main changes would be to let developers submit programs as unpackaged Win32 apps, rather than having to convert them to the MSIX package format—which itself was introduced to fix the issues people had when everything on the Windows Store had to be a UWP app.
With luck this would mean users could access and alter the folders games install to more easily, making Game Pass for PC simpler to manage (currently whether it installs games to your SSD or defaults back to C drive no matter what is a crapshoot), and making mods easier to install (currently that relies on developers enabling it as an option, and even then certain mods don't work).
The other big change is that developers would be able to host software on their own content delivery networks, rather than having to use Microsoft's in-app commerce platform. Windows Central's sources even tell it that, "Microsoft will not take a cut from app developers who do leverage their own in-app commerce channel". It's interesting this rumor appears as Apple is about to face the US Senate over antitrust concerns regarding the iOS App Store and is going to trial with Epic over the issue. Epic is demanding developers be allowed to handle their own payment processing—if this really is Microsoft's plan, we could even hear Epic bring it up in that trial.
The new Windows Store is expected to debut at the same time as a forthcoming refresh of the Windows 10 UI that is supposedly codenamed "Sun Valley", and is expected in Fall 2021.