Personally, I felt that unless a bank suddenly decided to start a campaign to filter out those who don't meet the target one, if not, most likely is up to your RM, perhaps to force u to obliged for their own benefits
Heard that RM will "blackmail" with the charge first, if u are willing to pay, then don't think anything will happen, not sure the $50 go to RM's pocket or to the bank? Anyway, if u are willing to pay $50 a month for the bank to do nothing, as a bank, I probably won't object to let u stay lo, esp if u are not getting any benefit much.. LOL.. If u don't want to pay, then either maintain what is needed or downgrade to avoid.