Medicos have been pushing the need for Vit D here in Australia for ages. It's not hidden.
I've read the links you've posted on Vit D and CoVid19 and all of those studies highlight that the further you go down the CoVid path the lower your Vit D. Nothing in those studies shows that showed that Vit D conferred immunity though clearly having the right amount of vitamins in your system is a good thing. And if you're in hospital for 2 or 3 or 4 weeks being treated for CoVid19 and aren't out in the sunshine and aren't eating foods boosting your Vit D what do you think happens to your Vit D count?
