Probability of Gaussian Naive Bayes
I'm not familiar with sklearn NB methods but it's likely that these are actually the predicted probabilities. NB is known to often assign extreme probabilities, i.e. close to either 0 or 1. This issue implies that the probabilities predicted by NB are not really meaningful, i.e. they cannot (usually) be interpreted as "there is an x % chance that this instance belongs to this class" for example.