Google changed to a Cloud API for Google Maps in 2018 and since then terms and privacy policies have changed, but for GDPR there has not been a solution yet, without blocking the API before loading.
Google Maps and WordPress
Most Google Maps plugins for WordPress, and themes, have included the new API and removed the implementation of an iFrame. Blocking the implementation of an iFrame is much easier than blocking the implementation with an API. The iFrames were mostly universal and easily recognized. Blocking an API and adding a placeholder is a bit trickier.
One of the most popular Google Maps plugins is WP Google Maps.
It’s also one of the few which added their own GDPR settings. Complianz adds compatibility to WP Google Maps by controlling the GDPR settings and adding a placeholder.
Example of WP Google Maps and Complianz
Below map is added by WP Google Maps using the API by Google Cloud Plaform. The placeholder and consent management is Complianz’ improvement on the plugins GDPR settings: