By 30 July 2017 UCITS will need to comply with the terms of the ESMA Share Class Opinion.
Helpfully, the Central Bank have indicated in their Q&A that prospectus updates can be carried out "at the time of the next update of your prospectus".
But away from the prospectus disclosure/transparency aspects, UCITS should also be reviewing their operational processes to ensure their share class currency hedging techniques comply with the provisions in the Opinion (and the Central Bank's corresponding Guidance, as updated on 28 June 2017).
In the case of UCITS, the responsible person should also ensure that under-hedged positions do not fall short of 95% of the portion of the NAV of the share class which is to be hedged and keep any under-hedged position under review to ensure it is not carried forward from month to month.