Well, no.
I don't think it's so much of a "new" thing. It's been done for awhile, but I think it ebbs and flows.
My mother SAH in the 70's and 80's when I was a kid. Only really went back to work when my Dad got laid off 2x and his final salary was <1/2 it was prior. Even with a paid-off house, they couldn't make it work.
When I had my first son in 2006, I was one of 3 women in my mom's group of about 50 to go back full time at 3 months. And boy did I feel the judgment. But I was in an industry and a company that wouldn't work with me otherwise. I *wanted* to work but felt maybe part time was better.
Interestingly, when my boss left to start a new company, my new boss was fine with part time. I was right. For me, it was better. My son was 17 months when I switched to 30 hours a week. 2 extra hours a day was awesome for going to the park, grocery shopping, cooking, playing, etc.
At that point in time, there were two women at the company of 30 who worked part time. Our boys were the same age.
When my son was 2, we had some management changes.
-My new boss said "I don't believe in part time, it doesn't work".
-Me: Well, it does for me.
-Him: "Sorry".
-Me: But she does it too.
-Him: "Well, she's not in a technical position."
-Me: She has a PhD in Materials Science, how is that not technical??
So I quit, and ironically got a job for my old boss at the new company, working part time. I worked PT until my son was 3, then they pressured me to go FT.
At the old company, another woman had a baby, and they allowed her to work 25 hours a week after she went back. Step in the right direction huh? But then they pressured her to go to 30. And then they pressured the PhD to go full time, and kept piling on the work. So, the PhD left to do consulting, and the other woman quit to SAH.
Fast forward a few more years and ANOTHER woman had a baby, and just went back to work (it's been so long now that she started after I left). They are allowing her to work 20 hours a week. My friend the non-PhD and I were having lunch and said "hey, finally some progress!"
-Anyway, I had a surprise 2nd baby at the new company 2.5 years ago, at the ripe old age of 42. I went back at 25 hours a week for a month or two. I learned my lesson, right? Then I went to 32 hours a week (30 is what you need to keep your benefits). At one year after my son was born, I was getting pressure to go back to full time. I was managing a group, and felt that I was needed. I worked with my awesome boss to transition to it. Literally a week after I went full time, they laid off my entire group and the President said "you can give 120% now right?" I just about smacked him.
Needless to say, I regret going full time. I now am 2 bosses later (I've had 7 in 6 years), and he won't let me go part time again. Blech.
I'm all about equality, empowerment, women getting ahead. I think there are still a lot of problems with equality, and I've experienced it myself (that glass ceiling HURTS I'll just tell you that). But for me, right now, since I'm now allowed to move "up", I'd like to just do my job, get paid less, and get a little more time off. As it is, I use ALL of my paid time off on school holidays, sick kids, school functions, etc. I rarely actually get to go on vacation.
I like working. I like having a back-up plan. I really don't want to be a SAHM. So for me, PT is pretty much where it's at. But I've got plenty of SAHM friends and it works for them.