A lot of this type of thing isn't clear yet and will be worked out when GDPR is enforced. At my previous employer, we took a pretty comprehensive view and trie

A lot of this type of thing isn't clear yet and will be worked out when GDPR is enforced. At my previous employer, we took a pretty comprehensive view and tried to play it safe, so at the very least any non-anonymous data in training sets would qualify. That does, however, already beg the question of why on Earth you'd need to train a model with non-anonymized data in the first place!