It can be beneficial for development. Particularly if you consider the osteopathic implications. The tongue is a very powerful muscle and the rhythmic suction generated results in an ebb and flow to the surrounding structures. This likely assists the cranial and facial bone structures in articulating properly and symmetrically. This prevents, and can resolve, cranial nerve impingements that occur positionally and at the time of birth. Prenatally this also likely promotes development of a strong latch ability. An infant who can feed effectively would have the advantage of lower risk of morbidity and increased survival postnatally.