Hey Meg,
Event will only happen in 2019 June, but I have researched about the event and also I have applied to the event as a model. I have big expectations about this event. It is possible to become a model, to make some great connections and to have some material for my portfolio. The instagram page of World Modelling Convention is active most of the time and they have some cool people already who will be a part of the event. If you are interested here is a link to it:
www.instagram.com/wmclondon/
After I applied I have received an answer from them in 2 days. And I was invited to the event! So I believe that it is absolutely legit and you can apply. Are you applying as a model?