Ive heard that one but I dont think its true. With my daughter if anything she got more active at the end. Every baby is different though as is every pregnancy.
I've heard it as well, and it was kinda true for me. My baby was really active for two weeks before labour, then three days before labour she barely moved. I wasn't even able to count kicks like I needed to.
I don't think it's true for everyone. For my friend her baby kicked all through labor even as she was pushing. My baby is never active she's always laZy and only moves when she has hiccups or when I have extremely full bladder.
Do they say that because maybe the baby is resting more in order to store energy in order to help during labour?! Cuz a baby needs to put some work into it too right?! I can't see them not moving at all but maybe just not as much because they're preparing themselves?