I'm not so sure the bug report being discussed is anything so simple, but I took on your little experiment.
CONCLUSION
It would seem, in this simple case, that no one has much to be proud of concerning interop between the different native formats. It is odd that the worst case here is the DOCX output from LibreOffice read back into LibreOffice. But Word 2010 doesn't round-trip to and from ODT a lot better (although it is a lot easier to adjust manually if desired).
To get this right, there needs to be a more-systematic effort that determines what discretionary provisions are being handled differently and what other features at the format level would be more successful.
DETAILS
I started in LO 3.3.2 Writer by inserting a frame around a paragraph of text, then saving it as a Microsoft Office Word 2007 DOCX format. The text box is centered at the top of the page and I adjusted its width so the text "This is going to be a simple text box" was in two lines. The box was vertically more than two lines though. (The automatically-created initial frame was narrower horizontally.)
The DOCX opened in Microsoft Office Word 2010 just fine, exactly as formatted in LO3.3.2 with the extra space at the bottom of the text box but with a thinner border line (looks like 0.5pt instead of 1pt).
However, when I opened it in LibreOffice 3.3.2, it produced a different, page-wide paragraph with a border around it. I can find no text frame.
Because I didn't keep a copy in ODT format, I did it again,
The LibreOffice 3.3.2 ODT Saves and Reloads just fine, just as I formatted it. I also see that the 1pt line is preserved and is heavier than I see in Word 2010. I examined the ODT Zip Package and confirmed there is a <draw:frame> containing a <text:box>. In addition, it sets a minimum height of the box. When I open that ODT in Word 2010, it opens fine except the text box is shrunk vertically and the outline is not so heavy.
I also saved the second ODT from LO 3.3.2 in OOXML DOCX (not the Word 2007 DOCX flavor), just to see what difference there is, if any.
It opens back in LibreOffice 3.3.2 once-again with the frame lost and there being a single-line paragraph with a 1pt border around it (full page width, one line high). I inspected the ODT Zip package and confirmed that LO turned the text frame into a paragraph with a solid border.
Word 2010 still has the centered box with the original height (blank space below the text) but it looks like the border is an 0.5 pt line.
For fun, I used Word 2010 to save the opened .DOCX document as a Word 97-2003 DOC and as an ODF Text .ODT document. Word 2010 reopens the .DOC just fine. On re-opening the .ODT, Word 2010 shows a drawn text frame that has been reduced vertically to surround the text.
On reopening the ODT from Word 2010 in LibreOffice 3.3.2, the frame is preserved but the border shrinks vertically to just fit the two lines of text, although I can see that the text box is vertically deeper than that still. The border is heavier again.
When I open the DOC from Word 2010 in LibreOffice 3.3.2, the frame is preserved and its border is the heavier one that we started out with. The border is heavier again.
![[TEST] Document Foundation Community](https://communitytest.documentfoundation.org/images/discourse-logo-sketch.png){kind=logo}
