Part of helping underserved communities would be to move some of the business outside the Valley and major metro areas. Find the mid to small cities and spread the wealth.
I'm not convinced what's happening in SF, and starting to happen in Oakland, is actually desirable by the residence that were there before tech people showed up.
I think it's much better that Jack donates to help public schools, libraries, arts & crafts, other recreational activities in underserved communities.... without sending the gentrification catalyst into them.
A similar phenomenon can be seen in the DC area, all the companies are hyper-concentrated in NoVa creating a miserable commuting situation for hundreds of thousands of area residents, meanwhile a city like Baltimore a mere 40 miles away is completely ignored when it comes to locating offices.