Any new format is obscure and untested.
TCP/IP was obscure and untested at one time.
HTML was obscure and untested at one time.
Actually, let's just call it obscure. I have tested several OpenDocument formats and they work just fine.
OpenDocument is simply a set of open XML based formats for word processors, spreadsheets, presentation software, and other productivity software.
As it is open and XML based, it is trivial for any productivity software to support it. I mean every word processor out there supports HTML.
Microsoft Office supports multiple document formats. I don't know if Microsoft submitted its own XML based file formats to the OASIS standards organization for consideration, but all Microsoft has to do is support OpenDoc.
OpenDoc is something that has been needed for some time. Many people simply don't understand why an HTML web page can be viewed in any web browser, but after 25 years of PCs, office documents have a myriad of different formats.
Which is why it's not a good idea to mandate an entire state government to use it, with no alternatives allowed.