We can only speculate as to the future of delivering content for installation purposes in a .net setting. However, we have some new information from nuget.org. The deprecation of content files and powershell in project.json makes sense.
If we speculate about the next version sharepoint version, then we might think about sharepoint projects using project.json and perhaps bower. Since bower as an ecosystem has tremendous growth, it might be the package manager of choice for this specialized task. We already see .net teams using bower for popular css and js libraries.
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