Getting configurePhpcs is not callable after update drupal to 8.3.2
I assume, that after the Drupal core update, you've overwritten composer.json with your previous settings.

However, in Drupal 8.3.2, configurePhpcs has been deleted. This part of composer.json (around line 69 has to be changed:

"scripts": {
    "pre-autoload-dump": "Drupal\\Core\\Composer\\Composer::preAutoloadDump",
    "post-autoload-dump": [
        "Drupal\\Core\\Composer\\Composer::ensureHtaccess",
        "Drupal\\Core\\Composer\\Composer::configurePhpcs"
    ],
    "post-package-install": "Drupal\\Core\\Composer\\Composer::vendorTestCodeCleanup",
    "post-package-update": "Drupal\\Core\\Composer\\Composer::vendorTestCodeCleanup"
},


You have to delete configurePhpcs line (and the comma at the end of the line above, so it should look like this:

"scripts": {
    "pre-autoload-dump": "Drupal\\Core\\Composer\\Composer::preAutoloadDump",
    "post-autoload-dump": [
        "Drupal\\Core\\Composer\\Composer::ensureHtaccess"
    ],
    "post-package-install": "Drupal\\Core\\Composer\\Composer::vendorTestCodeCleanup",
    "post-package-update": "Drupal\\Core\\Composer\\Composer::vendorTestCodeCleanup"
},


Then, you won't see the message anymore.