Incorrect. This individual does not qualify for a YP visa. Since they already had a WHV, they can only participate a second time under the Co-Op stream. YP is not possible. These are the specific rules for those from Ireland.@Keoghl7, from my understanding you could use an recognised organisation (a good UK one is Bunac and I think it includes Ireland too as their help area) to get a YP permit as a second IEC participation. It's approx. $1000 plus biometrics etc compared to getting a second WH which would be around $5k. This is what I've been suggested by IRCC to do based on being in a similar situation to you. The applications open for YP second help from Bunac on Jan 15th.
Hope this helps - let me know how you get on with your situation, would be a great help to me preparing for a similar one in a few months!
https://www.cic.gc.ca/english/work/iec/eligibility.asp?country=ie&cat=wh&#country_category_name_cont
As an Irish citizen, you may participate in the Working Holiday category only once. If you meet the eligibility criteria, you may participate in IEC one more time through the International Co-op (Internship) category.