Agreed that a lack of actual details about good gnolls vs. evil gnolls is a fail, but hey, baby steps. At least they have an origin separate from Yeenoghu now!
Adding the word “many” to the description of evil gnolls doesn’t actually do anything to shift the lore. Show is what the non-evil gnolls look like, don’t just tell us they could theoretically exist somewhere. Then give us PC stats for them.