It's not enough to ask if you have the four freedoms or not. There's more.
To quote from the Free Software Definition: Free software does not mean "noncommercial". A free program must be available for commercial use, commercial development, and commercial distribution. Commercial development of free software is no longer unusual; such free commercial software is very important. You may have paid money to get copies of free software, or you may have obtained copies at no charge. But regardless of how you got your copies, you always have the freedom to copy and change the software, even to sell copies.
Therefore, in order for a program to be free, the user must be able to exercise all four freedoms on a commercial or non-commercial basis.
Mozilla's trademark policy forbids the user from exercising freedom #2 on a commercial basis, rendering the Mozilla-branded version of the software non-free.
Of course, someone can always rebrand the software and get out of this (like Trisquel does) and anyone that is in possession of this modified version does have a free program but the Mozilla-branded version still has that problem.
