If you still have MS Office 2007 or more recent on your machine then there is no real need to get rid of it and it might sometimes get better results when trying to open these sorts of files. Such files often contain proprietary or binary blobs that make such files incompatible with any program other than the version of MS Office they were initially created with. A file created on MS Office 2007 might have trouble opening on MS Office 2010 or 2013 or 365. Sometimes LibreOffice struggles more and sometimes it is the only program that can successfully open such files. So keeping both suites keeps your options open.