Yes, it seems that the gesture detection is based on the raw time-frequency sEMG signals with data and code for model implementation from the Nature paper available here [1],[2].
[1] sEMG data:
https://fb-ctrl-oss.s3.amazonaws.com/generic-neuromotor-inte...
[2] Code for exploring surface electromyography (sEMG) data and training models associated with Reality Labs' paper:
https://github.com/facebookresearch/generic-neuromotor-inter...