You can always try.... but the end result will always depend on the CS on the other side. Whether they want to help or not... or whether they want to get a faster-ending call and say
'no more offer'...
You can point out you have been a longtime loyalty customer, prompt in payment, etc... but in end, they might just say 'so you want to recontract as per advertised, or not'

So you have to have a backup plan.....
This is just an extra they put in. And be reminded, it isn't unlimited. It is only 1Gb data. Make sure when (or if) you get and use it, you install that App where you can constantly check on ur data usage for this. Watch a few youtube videos, you will exceed that and have to pay extra $$$$.... Thus, you know why only now this is included.
Previously when i was asking them abt this, the CS told me no... if i want the 1Gb mobile BB, i will have to pay $14.90.