I highly doubt that. Microsoft has been embracing a lot of things lately. Moving towards Open source and open platforms. I don't believe it has anything to do with LibreOffice but everything to do with change in their attitude.
I'd say that competition prompted that change of attitude. LibreOffice is part of it. We've been raised with Word and Excel, then we discovered that LO and GoogleDocs were enough in the vast majority of cases and Windows was not necessary. Microsoft could be late with going were people moved to. Not too late, but they can count they money they didn't get.
To say that LibreOffice was anything more than a very marginal part of Microsoft's decision to refocus is laughable. The real threat to Microsoft is the movement towards BYOD for corporate customers. If users are bringing their own devices, then Office has to work on whatever devices those users have. Corporate customers aren't switching from Microsoft Office to LibreOffice. They're switching from Microsoft Office to Google Apps, or other hosted systems. Bringing (a better) Office experience to Android is Microsoft building a bulwark against Google Docs, not LibreOffice.
