Since the article is vague, two opposite speculations arise:
Some leftist bureaucrat is doing this to make a statement about Trump’s ban on immigrants from certain Muslim terrorist zones; or,
The applicants being rejected are not actually Irish, but transients from the certain Muslim terrorist zones the Irish want to be rid of.
Other possibilities?
The other issue not being mentioned is that the Irish govt. is being flooded by applications for Irish passports by UK citizens who want to cover their work options after Brexit. Apparently if you can prove Irish heritage back a generation or two and pay some money (about $1000 IIRC) you can get an Irish passport issued to you.