It's an anecdote for your argument. If the argument was "did Singapore discriminate against people through housing" it wouldn't be. If the argument is "should we have public housing [here]" then it's an anecdote. You'd have to show that this would happen in the place in question. If you want to make a general statement, you'd have to make that clear and make the case that in such countries landlords wouldn't discriminate against you for being LGBT (which they absolutely do).
Your definition of ‘anecdote’ seems way off to me. We’re talking about an objectively verifiable data point. Just because it doesn’t fully confirm some argument that someone’s making doesn’t make it an anecdote. Check the dictionary definition.
The definition of 'anecdote' has nothing to do with arguments. 'Anecdote' isn't a back formation from 'anecdotal argument'.