I love people who think they have a commitment from a big team for their 8th grader. All that is the big colleges trying to stop a player they think might help them from looking around for the next few years - and then when a few do develop then we get the story about how they committed when they were 13 and ignore the 20+ other girls that were also 'committed' to the same school but didn't end up there. Parents coming through the process hear the 'success stories' but talk to the people who have been around the process for years and they have 100 warning stories for every one that worked out easily. Early verbals help colleges (and parents egos). That is really about it - a few exceptions of course, but not many.
Said this a few times. If there is something better out there and it becomes available, your 'committed in 8th grade junior' is going to be out of luck. But then you will not want to cause issues because you now have to go on the market again - you will say "School X wasn't for us, so we are looking at new options" and then when you find your next school that will then cascade through a bunch of other kids who thought they were headed wherever.
Or coach changes or AD changes or the kid quits softball or can't academically qualify and so on...
Until you have the NLI signed and you have officially been accepted and enrolled into the university, you really have nothing more than a kind of half-promise.
The big thing to remember if you are 13 or 21 is colleges are always trying to find your replacement. Until you play your last game for a school they are always looking for someone a little better. They have been looking to replace their 2017 signing class for the last three years.