can I include user information while issuing an access token?

You will need to implement a custom TokenEnhancer like so:

public class CustomTokenEnhancer implements TokenEnhancer {

    @Override
    public OAuth2AccessToken enhance(OAuth2AccessToken accessToken, OAuth2Authentication authentication) {
        User user = (User) authentication.getPrincipal();
        final Map<String, Object> additionalInfo = new HashMap<>();

        additionalInfo.put("customInfo", "some_stuff_here");
        additionalInfo.put("authorities", user.getAuthorities());

        ((DefaultOAuth2AccessToken) accessToken).setAdditionalInformation(additionalInfo);

        return accessToken;
    }

}

and add it to your AuthorizationServerConfigurerAdapter as a bean with the corresponding setters

@Configuration
@EnableAuthorizationServer
protected static class AuthorizationServerConfiguration extends AuthorizationServerConfigurerAdapter {

    // Some autowired stuff here

    @Override
    public void configure(AuthorizationServerEndpointsConfigurer endpoints) throws Exception {
        // @formatter:off
        endpoints
            // ...
            .tokenEnhancer(tokenEnhancer());
        // @formatter:on
    }

    @Bean
    @Primary
    public AuthorizationServerTokenServices tokenServices() {
        DefaultTokenServices tokenServices = new DefaultTokenServices();
        // ...
        tokenServices.setTokenEnhancer(tokenEnhancer());
        return tokenServices;
    }

    // Some @Bean here like tokenStore

    @Bean
    public TokenEnhancer tokenEnhancer() {
        return new CustomTokenEnhancer();
    }

}

then in a controller (for example)

@RestController
public class MyController {

    @Autowired
    private AuthorizationServerTokenServices tokenServices;

    @RequestMapping(value = "/getSomething", method = RequestMethod.GET)
    public String getSection(OAuth2Authentication authentication) {
        Map<String, Object> additionalInfo = tokenServices.getAccessToken(authentication).getAdditionalInformation();

        String customInfo = (String) additionalInfo.get("customInfo");
        Collection<? extends GrantedAuthority> authorities = (Collection<? extends GrantedAuthority>) additionalInfo.get("authorities");

        // Play with authorities

        return customInfo;
    }

}

I’m personnaly using a JDBC TokenStore so my “Some autowired stuff here” are corresponding to some @Autowired Datasource, PasswordEncoder and what not.

Hope this helped!