I think at the moment there is the soft problem of delays in results or potential rejection for unknown reasons. You also don't have to tell them who you're staying with either but a rejection can be pretty devastating so there is a strong incentive to give more than what is explicitly required. It was clear such encroachments on civil liberates were coming so I've never done anything on my social accounts that would upset the establishment, so even in my own case it has had a chilling effect.

If my memory serves me right, it was mandatory to mention the first address I went to, but social media was clearly marked as optional. I put GitHub, it worked fine.

My point is that it’s unknown if not stating it would impact the application so people would err on the side of caution and compliance.