Office 365 is the online cloud hosted version of Office similar to Google Docs and include SharePoint Online, OneDrive and e-mail. With it, you get the ability to install the on premise or "full" version of Office which is currently Office 2016.
To answer your specific question, a later version of Office will not be required for ST10 to open files or operate other Solid Edge commands.
Office 2010 appears to work fine with ST10. There are no known issues. Of course, most all of our ST10 testing has been conducted with Office 2013 or 2016 installed.
If a Solid Edge ST10 and Office 2010 specific problem is reported, then we would try to resolve it for our customers. The only risk here is IF the fix required support from Microsoft, This would be more challenging to impossible, since Microsoft dropped support of Office 2010 in 2015. This is why we have to add such statements to the ST10 product readme file:
Some Solid Edge commands require Microsoft Excel. Solid Edge stops testing with Microsoft products shortly after Microsoft drops mainstream support for them. Microsoft dropped mainstream support for Office 2007 in October 2012. Microsoft dropped mainstream support for Office 2010 in October 2015. ST9 was the last release to support Office 2010. With ST10, we recommend Microsoft Office Professional 2013 or Microsoft Office Professional 2016.
I hope this helps,
Solid Edge Release Manager
@LauraWatson, That was extremely helpful. Thank you.
Edit: And I don't think it would be unreasonable to say to your customer having issues with Office <= 2010 vis-a-vis SE, "sorry, you'll need to upgrade Office".
That statement is correct. O365 is NOT supported. But don't get your undies in a bunch. O365 is only a brand name for the subscription to MS Office and other universal apps. So the question really should be "Is Office 2016 supported?"
O365 is a subscription policy to use and deploy MS Office 2016. Office 2016 can be purchased seperately but does not include the upgrades.
"All Office 365 plans for home and personal use include Office 2016 with the fully installed Office applications that you’re familiar with, like Word, PowerPoint, and Excel, plus extra online storage, ongoing tech support at no extra cost, and more." Straight from MS.