MS ends Win 7 support Jan. 14, 2020 ( 7 months )

It all depends on what changes Daybreak makes. Just because a version of Windows goes unsupported doesn't mean that everything on it will stop working. However, at some point, DB will make a change that Win7 doesn't support, and that's that. That could mean going to the latest version of DirectX, or changing compilers, to one where the runtime requires Windows 8 or 10.
(For example, Visual Studio 2017/2019 can still produce programs that'll run on XP. Getting there requires a fair amount of work, though.)