Not 100% right as some companies in EU member countries such as Finland, where I'm from, were allowed to use a certain clause that would allow them to still add

Not 100% right as some companies in EU member countries such as Finland, where I'm from, were allowed to use a certain clause that would allow them to still add roaming charges (mostly data related). This is done because the majority of operators sell contracts based on the speed and not a monthly GB cap. Almost all contracts are unlimited in data. I for one have a ~30€/month contract that has unlimited data with 50Mbps down / 30Mbps up. After the roaming change my contract includes ~6GB of roaming data within EU. When that's reached there is a 0.0057€ per MB price in data abroad.