No, they can't change it.
As long as you keep your side of the contract, i.e. pay all your repayments on time, there is nothing that they can do.
If it's an investment property and you are in arrears, they could repossess it or offer you changed terms to avoid repossession.
If it's your home, this would be very difficult to do because of the CCMA.
TRS;
Central Bank rules do not impact on the actual contract you have with the lender , the Central Bank rules/guidelines apply to the conduct of the account.
To be clear and as Brendan advises.
You keep up your payments as per the contract you are 100% safe.
It then matters little whose name is over control of said contract.
So rest easy !