The people affected by this have the following clause in their letters of offer:
3.2 Further Fixed Interest Rate Options/Choice
At the end of any fixed interest rate period, the customer may choose between:
a) a further fixed interest rate period, or
b) conversion to a variable interest rate Mortgage Loan, or
c) conversion to a tracker interest rate Mortgage Loan, at the Bank’s then prevailing rates appropriate to the Mortgage Loan
If you don't have this , then you are not in this cohort.
If you don't have this and you received the €1,650, then it looks like their mistake and you were not entitled to it.
Brendan