Latest Version of Microsoft Word

[OldGoat46]

Is there any plan to update the list of "save as" files to include the latest version of Microsoft Word?

[Zizi64]

The LibreOffice can save into OOXML formats.

Note: there is not 100% compatibility with foreign file formats.
Use the international standard ODF formats, if you want work efficiently with opensource office suites.

[OldGoat46]

I probably should have been more specific. Are there any plans to update Open Office so document files or spreadsheet files can be saved in the latest (Win 10) version of Microsoft Office Suite?

[RusselB]

Simply, we probably have no idea. We are end users, just like you, not developers.
You might want to post your query to the developer's mailing list. More details available here

[Zizi64]

Are there any plans to update Open Office so document files or spreadsheet files can be saved in the latest (Win 10) version of Microsoft Office Suite?

Ask the developers.

But this is not a simple task, because the OOXML Standard has two versions (levels): the Strict and the Transitional.
The OOXML was published in year 2008. The MS uses the Transitional version since the Standard was published.
The word 'Transitional' means for me (simplified): The MS can change it when and how they want... This is not a simple thing to follow the changes, without exact documentation...
I think the developers of the AOO will apply the OOXML format saving feature into the AOO, when the MS will use the Strict version (only!) of the OOXML Standard.

[Villeroy]

As long as MS fully supports their legacy doc format there is no technical reason not to use this format after 25 years of "co-evolution". If you want to save all your work in MS Office formats, Microsoft Office is the one and only product you can use anyway.

[Villeroy]

Always save documents and media in the native file format of your application. Regarding OpenOffice Writer this is Open Document Format with odt file name suffix.

Only if _all_ of the following conditions are true, you may decide to send a doc copy to someone:
1. The receipient is supposed to co-edit the document with you. If you want him to read your document true to the original on any phone, tablet or PC, send him a PDF copy of your document.
2. The receipient has no ODF capable software.
3. The receipient is not willing to install ODF capable software even though it is free.
4. The receipient has an old version of MS Word. Since 2013 MS Word can read and write our Open Document Format fairly well.

Supposed that someone sends a docx via email and you are supposed to co-edit this document while the above 4 conditions are met:
1. Open the attachment with OpenOffice
2. Save your own working copy in your own document folder. Your working copy is always ODF.
3. When done with editing, menu:File>Send>Document as MSWord and send back your edited version.
This way you always have the original doc(x) that has been sent to you in your inbox, your working copy and the doc version you have sent in your outbox.
For most MS Word documents doc is just as good as docx.