Does this mean they call the Google Maps API now instead (which microG does support to a certain extent), or does this mean they now require to have Google Maps installed as an App additionally? If so, did you install Google Maps?
Apart from some pilot project ending and a merging of Apps I did’t find much about it immediately.
Perhaps you might want to think about whether /e/OS is the right choice in this situation. Apps relying on Google Apps or services might work at some point in time on /e/OS with the help of microG, but this is not guaranteed, Google can break compatibility with changes on their side at any time for any given length of time, while microG would have to implement the changes, if at all possible.