Comment by matt_trentini

Yes, it was chosen for low size and memory constraints. But it is limited in features (like counted repetitions):

https://docs.micropython.org/en/latest/library/re.html

so alternatives to provide additional features have been discussed... Either extending the existing module or swapping to a more feature-rich library. Possibly even doing so for larger micros that can afford the additional flash/memory, though that makes support more challenging.