In an official statement from the Belgian Gaming Commision, they declare that lootboxes are gambling:https://www.gamingcommission.be/opencms/export/sites/default/jhksweb_nl/documents/onderzoeksrapport-loot-boxen-Engels-publicatie.pdf
With the definitions that they give, they make it clear that all lootboxes are now illegal in Belgium. They recommend criminal prosecution on this basis. (Note: They will not proceed with this until the Minister of Justice meets with industry stakeholders).
I would expect to see lootboxes pulled ASAP, but also to see legal challenges to several of the definitions that they have given. I am also not certain how this affects the EU in general vs just Belgium.