Few criminal defendants plead guilty or no contest at the arraignment stage; in most cases, the prosecution is just getting started.
Foster remains on leave from the 49ers while the legal process proceeds. 49ers G.M. John Lynch has said that if it’s proven with the court system that Foster committed domestic violence, Foster no longer will be a member of the team.
The alleged victim in the case has recanted the core claims against Foster; the question becomes whether other evidence would support a finding of guilt beyond a reasonable doubt.
As to the pending charge arising from alleged possession of an illegal assault weapon, the change of heart won’t matter. However, the consequences for Foster from both a team and league perspective probably would be less severe.