Preamble
Based on comments to my question, I've done some experiments in MS-Word 2019. This answer documents the result.
Edit 1
I've done the same test with MS-Word 2013 now. Differences see below.
Edit 2
I've found an interesting article aboutn quotation marks on Wikipedia. See references below.
Typographical Quotes by Document Langnage
The document language, more precisely the language of the text passage where the double qoutes are type, determines what characters are used as typographical quotes.
Text marked as "German (Germany)"
Opening and closing simple double quotes are replaced with low double quote („ - HTML „ - 0x84), and left double quote (“ - HTML “ - 0x93).
"Hello" becomes „Hello“
Text marked as "German (Switzeland)" - MS-Word 2013
Opening and closing simple double quotes are replaced with low double quote („ - HTML „ - 0x84), and left double quote (“ - HTML “ - 0x93).
"Hello" becomes „Hello“
Text marked as "German (Switzeland)" - MS-Word 2019
Opening and closing simple double quotes are replaced with left double guillemet (« - HTML « - 0xab), and right double guillemet (» - HTML » - 0xbb).
"Hello" becomes «Hello»
Text marked as "French (Switzerland)" or "French (France)"
Opening and closing simple double quotes are replaced with left double guillemet plus one space (« - HTML « - 0xab), and right double guillemet plus one space (» - HTML » - 0xbb).
"Hello" becomes « Hello »
Text marked as "English (United States)" or "English (United Kingdom)"
Opening and closing simple double quotes are replaced with left double quote (“ - HTML “ - 0x93), and right double quote (” - HTML ” - 0x94).
"Hello" becomes “Hello”
References
I found the following web pages explaining the different types of "double quotes":