By voting yes on the initiative, voters are approving a binding agreement that requires the developer to provide the public amenities it promises. (Source: Initiative, sec. 2(s); DA, exhibit 4; SunCal's campaign literature.)
The initiative does not guarantee that any public amenities will be delivered. The only guarantee in the initiative is that there are no consequences for haphazard development or no development at all. Section 2.9 of the contract states that the developer has no obligation to develop the project “at all or in any particular order or manner.”
If development proceeds, what would be binding is an obligation by the developer to fund (or “advance the funding of”) $200 million (contingent on certain conditions) for the public benefits listed in Exhibit 4 of the DA (sports complex; parks, trails and open space; on-site and off-site traffic improvements; ferry terminal and transit hub; improvement to waterfront and fire station, and a library branch). But since the amount pledged is clearly insufficient for ALL of the benefits listed, it is anyone’s guess what will be built and what will be left out.