The following is an extract from a much longer and more detailed list in the MyHeritage Blog:
We just added 8.3 million historical records in June from six new collections from the U.K., Spain, and New Zealand. Four million records from a World War I medal index were added from the U.K. Three collections from the Vitoria Diocese in Spain were added: a baptism index, a marriage index, and a death index. In addition, two collections from New Zealand were added: a World War I service index and an index of early settlers. This update brings the total number of historical records on MyHeritage to 12.5 billion.
Here are more details on each of the new collections: