It just seems like a "bait and switch" tactic. A Calvinist doesn't affirm "freedom from God" in any meaningful sense (namely, that there are decisions made out side of God's eternal decree and sovereign control), yet still claims to affirm "free will." I think many people who disagree with the Calvinistic position rightfully say that this sort of freedom isn't any freedom at all (in the sense being debated).
Though I do affirm the 5 points of Calvinism, I don't like the term "compatibilist free will."
That said, the referal to "free will" refering to a "freedom from sin" seems entirely appropriate outside of a debate/discussion on the sovereignty of God vs. free will. Romans 6 is an excellent passage of Scripture supporting the idea of "free will" as "free from the bondage from sin."
16Do you not know that if you present yourselves to anyone as obedient slaves, you are slaves of the one whom you obey, either of sin, which leads to death, or of obedience, which leads to righteousness? 17But thanks be to God, that you who were once slaves of sin have become obedient from the heart to the standard of teaching to which you were committed, 18and, having been set free from sin, have become slaves of righteousness.Paul, having walked through an entire argument about how all people are under the condemnation of sin, steps us through the way of righteousness which is found through faith in Christ Jesus. In chapter 6 he refutes an objection that such a person who has been saved by grace should continue sinning so that God's grace may be demonstrated even more.
"Are we to continue in sin that grace may abound?" he asks, and then he responds, "By no means!" and he continues with the argument to talking about how we act as slaves of sin or slaves of righteousness, and that we have been set free from sin by God. This is freedom, a freedom from this bondage of sin. No longer does it control us, no longer do we call sin our master, but we call God our master. (The question of sanctification is important as well, but not dealt with in this passage as much as Romans 7)
This is free will as Scripture demonstrates, not a freedom from God's decrees, but a freedom from the power of sin. And that's what God, in His grace, has done for us through the cross of Jesus Christ.