I have email from the programming team of the Dublin Worldcon. Due to restrictions caused by the GDPR legislation, they can’t get lists of programme particiants from other conventions and reach out to them. They have to wait for people to come to them. Therefore they are reaching out to the SF&F community and encouraging people to apply to be on programme.
You don’t have to be a published author to be on programme. And you defnitely don’t have to be an old, white man. If you think you have something interesting to say, please put your name forward.
You can find the application form here. And there is a Q&A about the process here.