I decided to limit visitors after birth whilst pregnant, as once I'd announced the pregnancy I was no longer a daughter or DIL, but an incubator for their grandchild, no conversation other than the baby, no asking how I was, just the baby.
1st time around we had quick hospital visits, and then a few days at home before I let anyone in, birth was straight forward, but it was exhausting, and I remember my family turning up en masse, at one point my mum asked if anyone wanted to cuddle my DC, I asnwred yes and it was like I had spoken out of turn, but I was made to feel I'd taken a gift off someone at Christmas.
2nd time around I nearly lost my life, spent days in hospital hooked up to every wire thinkable and still got asked when visitors could meet the baby. I was discharged with explicit instructions to rest, DH was to do everything, however the messages to visit were relentless including on behalf of others. I even got told I needed to forget and concentrate on my babies, yes forget that I nearly left those babies motherless.....so no it isn't a fad or latest craze, it's self preservation, it's that you no longer stay in hospital unless you are at death's door, it's the selfishness of others that forget a woman isn't just an incubator when pregnant or just a mum afterwards.
OP listen to your daughter, drop the occasional message asking after her, if she responds then ask about the baby, let her know that she is still your baby, remember how vulnerable you will have felt after giving birth, just think about her for a moment and then when she is ready enjoy giving her love and the lovely baby cuddles.