Based on what you received and highlighted, Maybank's statement is inaccurate as it should be reissued as "Maybank has its own minimum threshold for Each Individual". 

i received not even a single sms from MBB when I swiped one RM 5k and another RM 14k right before CNY with my VI.

Do you have any previous transactions with the merchant above where you swiped RM14K?

Received SMS from 62002 for using Citibank CC at GSC website:

DATE for AMOUNT - MERCHANT NAME. Pls call Citibank  if you have any query.

No, never before

After CNY trip, my banks(UOB,MBB) email me for all the petrol kiosk usage and makan trip usages.
Going to use in sg to test next week.
First thing to do is swipe SGD1.20 for coffee at mcdonalds

Noted  - Online Transaction.
Wah, how much do you need to charge to trigger SMS alert in your case.
Bro, email or SMS?

Submitted the OCBC SMS alert request form to change my minimum threshold and successfully received SMS for my transaction, all within one day. Kudos OCBC. It's a shame for Maybank, being one of the leading bank here, taking their customers for a ride.

How low did you change it to ? RM1.00 or RM0.10 ?

Based on what you received and highlighted, Maybank's statement is inaccurate as it should be reissued as "Maybank has its own minimum threshold for Each Individual". 

It is incorrect for my case. I made 2 transactions (both transactions are more than RM1,000 but less than RM1,500 each) within the same day. However, I only received one sms notification. How does MBB explain this?

which transaction triggered the SMS alert, the lower or higher amount? and both are face to face transactions?

i have not been getting any sms for any transactions, even ones done online. Even with OCBC, no sms when I traveled and pump petrol outside of my usual city.

for OCBC, you can submit the SMS alert form to reduce your minimum threshold amount. the form was given by ronnie at the OCBC ti thread 

http://forum.lowyat.net/topic/1791215/+1520#

Please allow us to clarify that the pre-determined amount is set by the Bank. Hence, we are unable to disclose the amount. Nevertheless, kindly be informed that an alert shall be sent for transactions where the card is not presented such as online transactions, auto debit or mail order transactions. For transactions where the card is presented, you may opt for your own preferred threshold amount which is to be lower than RM1,000.00 to safeguard your interest from fraudulent usage. Once you have opted your preferred threshold amount, all the transaction which is performed per the threshold amount you have opted for shall alert you with a SMS via your mobile phone.

RM0.00 MBB CUST XXXXXXXXXXXXXX####: YOUR REQUEST TO CHANGE OF THRESHOLD AMT MYR10 IS SUCCESSFUL