No the increase in quota is not permanent, the extra quota is only being offered for 3 months period:
Example a new customer who signs up to Broadband Monthly Rm100 will be able to enjoy quota of 68GB for 3 months from the date of activation after which the quota will revert back to 50GB.
An existing customer on Broadband Monthly RM100 will also enjoy the quota for 3 months from 22 Dec 2016 for 3 months. 3 months period will depend on the subscribers bill cycle and may vary for each subscribers. After 3 months period, the quota for Broadband Monthly RM100 will revert back to 50GB.