I am not a lawyer, but to me if you signed up for class action, and you agreed that the $125 check supposed to be the payment for your damages and the other party backed off and did not provide it that means the agreement shouldn't be valid.
Disclaimer: IANAL (but did go to law school and vaguely paid attention to this part so lawyers, please correct my recollections where wrong)
My recollection is that, usually, only a small number of people actively sign up to the class during the lawsuit & settlement negotiation phase, and the named class is guaranteed a substantially higher payout. The settlement is worded as up to $X for the rest of the class, who can choose to accept the fact that the amount is not a guarantee or decline and keep their ability to bring a subsequent action (hence my original question of "Can you bring subsequent class action suits comprised of different subsets of the same impacted class?").
So basically, the people who actively signed up are getting a guarantee of an amount they negotiated, the rest of us are stuck deciding how valuable "up to" $125 actually is.
