Loving v Virginia is far less of a stretch of the wording and intent of the 14th Amendment, especially given the context in which it was passed. I'd be open to be convinced that Obergefell is the necessary consequence of the Loving precedent, but I'm not entirely sure if I agree, and either way, this is about the Austrian constitution and not the US one.
It took 99 years for that ruling to come down after ratification, and even then, less than 20% of the general public supported the idea. I know this is off topic, but if the 14th Amendment was limited to just race based on original intent, I think it would say so. If
Loving had gone the other way and upheld so-called state's rights, I wouldn't discount the possibility of having areas of this country where interracial marriage was still illegal (or at least not recognized).
From my point of view, the Fourteenth Amendment does not require interracial marriage, same-sex marriage, etc. What it requires is that so long as the government offers the rights and privileges of marriage, those rights and privileges cannot be denied to interracial couples, same-sex couples, etc. I reject most originalist arguments, but I do consider myself to be a textualist.
To Tender Branson, what are the provisions of the Austrian Constitution being used to support this ruling?