Yes, but the FSLA which concerns fairness in pay, does not concern itself with terminations. So, while I appreciate the subtly of your argument, it doesn't legally work.
In Florida, you are an "at will" employee, which legally means that you can be terminated at any time, with or without cause. In that employment status, no you do not have the right to keep yourself employed.
An "at will" employee can be terminated for any reason or no reason at all, except for terminations based on race, religion, gender, age, disability or FMLA use. That list again, because the list is based on those statutes that actually make certain types of terminations illegal.
Legally, they could have terminated you for questioning the change in their marketing without using this metric at all. They legally could terminate you for liking the color blue too much or for preferring Snickers bars when Mars bars are the boss's favorite (I am not kidding here).
So again, I understand your question. I've practiced in this area of law for a pretty long while now. I sue employers for a living. The practice that you have mentioned is not illegal, on the facts that you have given to this point. If I could tell you differently I would, but I'm not going to lie to you here.
The employer, at this point at least and based on these facts, is not doing anything illegal.