Microsoft purchased CitusDB a while back, so you can expect many many contributions to Postgres to be from Microsoft now.
There's plenty more low grade shit in what was once a goof product.
I haven't used the features you discuss but then I need basic functionality to work. I've run into stupid performance bugs with trivial CTEs, and I found a link showing a CTE error which I could duplicate (pgres got it right, mssql didn't). Can't find link, sorry.