I'd much prefer the school to have fun morning activities before class (games in the computer lab, for example, bonus points if you can tie that into learning without the kids realising it) while having an official starting time that is late in the day. This covers kids that have to wake up early due to their parents schedule, but lets kids that can sleep, well, sleep. If the days are going to be longer, is there more recess? More downtime? More art and music and otherwise "fun" stuff? These things help with learning. Same for after school, honestly.
A great bonus that is included is support for schoolwork that is missing at home. I'd rather have a no-homework school in lower grades as it makes more sense, but this is the next best thing.
I might also mention that these are 2nd and 3rd graders. I don't know if they are the sorts that are actually susceptible to gang violence outside of what happens around them. They do, however, have the issues poverty brings up, which is what the school seems more geared towards. Food banks, job help, GED help, and free counselors for those that have endured trauma, which comes in many different forms outside of gang violence - poverty is one predictor of having it.