Currently, the https://the-guild.dev/graphql/apollo-angular/docs/local-state/management page says that Local Resolvers are deprecated. However, Apollo Client documentation has no mentions of their deprecation. Instead, it only mentions that the feature is going to be moved out of the core module (which means that it's still going to be supported): https://www.apollographql.com/docs/react/local-state/local-state-management
Therefore, apollo-angular docs are currently misleading. The local resolvers are not deprecated and are going to be supported in future. The apollo-angular documentation has to be updated with this regard.