No, diversity training should be encouraged but not required

Diversity training is important for empathetic and understanding teaching and creating a supportive and fruitful environment

A child has a right regardless of who they are to feel understood and respected in an academic environment. This trumps the feelings or time of an adult of free will deciding to work in the education sector. Adults in this environment set the tone to how this child is treated. A child who feels accepted is more inclined to accept the new country or majority groups culture and beliefs. Hence, assimilating with a lesser chance of committing crime/working/ paying taxes and improving the home country and promoting/embracing in their own way the culture of their new home. LGBT people exist regardless of environment. Feeling welcome will mean better mental health and less strain on the mental health system.

Ireland should welcome people from different ethnic backgrounds and that should be supported by the teachers in the country.

Teachers & Educators primary role, as I see it, as someone in the profession, is to at the very least not alienate or ostracise or make to feel less-than the young people they work with. This means being helped to understand things around gender identity, pronouns, sexual orientation, religion, so on. Get over yourself and practice more empathy. Do what's kind for young people. Simple.