If you prefer local storage, don't worry: you can get back the traditional way of creating documents, in which they're not saved to the cloud until you choose. In Word for Windows, click File > More > ...

Microsoft says that Word for Windows will soon enable autosave and automatically save all new documents to the cloud by default.

When AutoSave is enabled, Word will save a document to the cloud right away. The name of that document will be based on the date. You can then change that file name or the location where the file is ...