She seems to have faced zero consequences. In the first film, Carrie yelled at her for dumping Steve, after *he* cheated on her! Now, the most we get is a mildly surly comment from Brady. All her friends are just complacently accepting and her husband could not be more accommodating.
On the reuse of actors - this is reasonably common in East Coast US shows. And it happened in the original series. Most memorably, Justin Theroux played two different characters
I think the thinking behind this is it's lazier than showing up and putting some graft in; it's an easy option for a rich person. In reality, while that line of thinking might have some truth for things like protest and campaigns, the average charity can make much better use of cold hard cash compared to having to manage an untrained, one-day volunteer.
It set up a decent line for Seema at least.