A new version (V3) of MobileNet is already out since a while now:
"Searching for MobileNetV3" on ArXiv

Public pytorch implementations are already available here:
https://github.com/d-li14/mobilenetv3.pytorch
https://github.com/kuan-wang/pytorch-mobilenet-v3

However they don't achieve accuracies on the level as the ones mentioned in the paper but the following implementation seems to be on par with the paper:

https://github.com/rwightman/pytorch-image-models/blob/master/timm/models/mobilenetv3.py
https://github.com/rwightman/pytorch-image-models/blob/master/results/results-all.csv

Could MobileNetV3 be added to torchvision?