xlsx and docx are the current Office file versions. There is no end date that has been set for opening those files in Office.
pdf, msg, bmp, txt, csv and eml are long-standing formats with no proclaimed sunset date for their useage.
Only xls and doc are old formats. Some of those versions are, by default, not openable in modern versions of Office. However, in any Office program, you can choose File>Options>Trust Center>File Block Settings, uncheck all options and still open most of those files. Only Office files from the early 90s or earlier may not be openable in modern versions of Office due to security concerns. For those, a copy of Office 2003 should be able to open very old files.