In a comment, Janus Bahs Jacquet wrote that:
[Y]our phrasing makes it sound like a) you’re deliberately going out of your way not to disclose the person’s gender, or b) you know and respect that they is the person’s preferred pronoun. Both cases are definitely marked, though. This way of phrasing things would never be seen as neutral or unmarked in most contexts.
The default and unmarked way of referring to people you know (and whose gender you can therefore also be assumed to know) is by gendered pronouns, since they are used by the vast majority of the population.
