In recruiting there are always a few juniors (and younger!) who absolutely know where they want to go and as soon as that school offers, they give a verbal commitment, but the vast majority of them do not have that ultimate one school (or that school has not yet offered them.) Typically juniors wait until after their HS season is over, and a lot wait well into summer. Some, like possibly a certain gem stone, may be waiting till after the HS season so that other players on her team get maximum exposure during the season. Others may want to get past the season before they really look at where they stand and what they want.
We have been occasionally lucky with early commits, but we have also been unlucky a few times when those early commits changed their minds. I suspect having been burned a couple of times on high profile commits, Geno is more likely to say to a recruit 'We really want you and here is an offer, but please think about this carefully - do not make a commitment yet unless you are really positive we are the right choice for you. The deadline on this offer is September (or sometime in the future, or there is no deadline) of your Senior year, so you do not have to feel any pressure to commit right now. We want you to make the right choice, not a quick choice.'