Can Word open a .odt file?

According to published magazine articles during the evolution of the standard, Microsoft was late to the table with their OOXML proposal and really didn't expect it to become the standard. Microsoft planned on and built support for ODF into Office 2007 based on the assumption that ODT, not OOXML was most likely to be chosen as the open standard.

That again doesn't make sense. At that time MS already had a working implementation of ODT. If in addition to that they also expected it to become the standard for both ISO and ECMA, why should they waste time and resources on OOXML?

According to published magazine articles during the evolution of the standard, Microsoft was late to the table with their OOXML proposal and really didn't expect it to become the standard. Microsoft planned on and built support for ODF into Office 2007 based on the assumption that ODT, not OOXML was most likely to be chosen as the open standard.

That again doesn't make sense. At that time MS already had a working implementation of ODT. If in addition to that they also expected it to become the standard for both ISO and ECMA, why should they waste time and resources on OOXML?

You have it almost right, but your time-line is a bit off. Microsoft went forward with support for ODT in Office 2007 (for Windows) which is why there is pretty good (but imperfect because they stopped working on it in the middle of things) support for ODT in the Windows version of Office. Since Microsoft had invested in support and ODT was working fiarly well, they just left it in the product.

When OOXML instead of ODT  was adopted as the official standard for everyone Microsoft had to change their design for Office 2007 (Windows) mid-stream and build around OOXML instead of ODT. Consequently, Office for Windows has some ODT support. Development of the Mac version of Office 2008 started a year later. By then, the accepted standard was OOXML instead of ODT, so there was no point in building ODT support into Office 2008 or any later edition of Office for Mac.

Don't accept the Microsoft line -- the false premise -- that there is a "the standard".  Multiple formats can be certified as an ISO and ECMA standard.  Their claim that the certification of OOXML makes ODT obsolete is just propaganda.  ODT remains a ISO standard.

Now that Microsoft has obtained standards approval for their proposed file format, they have stopped supporting ODT to attempt to force all other Office applications to use their file formats.

It is unfortunate that the supposed moderator is using a forum to disseminate Microsoft propaganda.

I was around, live and well during the entire process when the standards were selected. I followed the process in the press and in newsgroups at the time. 

See 

Standardization of Office Open XML and if you are really interested visit a library and review trade publications from the time period of the standardization process.

The process of choosing a standard was insisted upon by ODT advocates before the standardization process even got under way. ODT advocates were having a field day chastizing Microsoft for their proprietary .doc .xls and .ppt binary file formats. Open source advocates even managed to get entire countries (notably Germany) to switch from Microsoft Office to open source OpenOffice primarily due to the supposed evils of Microsoft’s proprietary format. ODT advocates pushed hard to get ODT labelled by an international standards body as the file format to use, giving OpenOffice a competitive advantage over Microsoft Office.

It is understandable that the ODT advocates felt betrayed by the standards body’s choice of OOXML over ODT. After all, the standards body was packed with ODT supporters and they thought ODT was a shoo-in. When the standards body unexpectedly chose OOXML over ODT because OOXML is more open and has greater capabilities than ODT, ODT advocates were livid and haven’t gotten over it to this day. 

ODT is not an abandoned standard, as you point out. The standard is still active. However ODT is not the format everyone should be using for word processing, spreadsheets or presentations these days. The format that was endorsed by the standards body is, in fact, OOXML, not ODT.

OOXML is not a Microsoft file format. It is an open human-readable text file format based on XML that was proposed by Microsoft to the standards body as a better alternative to ODT, which is also based on XML. Microsoft makes no claims that OOXML is for Microsoft products only and does not brand OOXML as Microsoft OOXML. LibreOffice, TextEdit and many other software programs use OOXML now. 

You say: “Microsoft has obtained standards approval for their proposed file format, they have stopped supporting ODT to attempt to force all other Office applications to use their file formats.” I think that is untrue on its face. ODT is supported in Office 2007, 2010 and 2013 for Windows. Microsoft stopped using their own formats beginning with Office 2007 and have defaulted to the open standard OOXML file formats ever since. Something even OpenOffice and LibreOffice have yet to do.