Re: Of course it won't get rid of MS
Yes, LibreOffice can track changes and present it as markup. Don't use OpenOffice, but ODF allows it.
This is is a win for choice, not for a specific product.
MS Office will still be a good choice for some businesses and Government departments, but it is no longer the only option.
DOC is an opaque format that nobody in the world really understands - the only documentation is the combined source code of several versions MS Word.
MS-OOXML contains some of those unknowable chunks of DOC in it as binary blobs, thus cannot be fully implemented by anyone without access to MS Word source code, and several parts are covered by MS patents which they charge for.
ODF is a complete and open published specification. All of the information needed to create a complete implementation is publicly available to anyone who is interested, and you do not have to pay anyone for any patent licences. You can even download a copy for free if you so desire.
Secondly, even today it is very difficult, if not impossible to read DOC files from early versions of MS Word, because you need to gain access to a string of different versions of MS Word - even if that is still technically possible, it's almost certainly impossible to do legally.
Yet in 30 or even 300 years time it will still be possible to read documents stored in ODF, even if none of the currently-extant programs are still available.