I agree that the "angelos" could be false prophets, but I think the better reading is angels.
First, look at the progression of Peter's argument. There is no biblical reference to pre-Noah false prophets being thrown into chains and kept for judgment. He moves forward in time with his examples, not backward or out of order. It brings to mind Jesus' own statement that He saw Satan fall as lightning from heaven. Without serious challenge, this was pre-Fall of Adam. So, the weight of Scripture seems to me to favor angels in 2 Peter.
Consider the parallels with Jude 6 as well. Peter may have relied on Jude's epistle for much of what we see in 2 Peter 2; it could be the other way around. Point is that reading Jude 4-19 is almost verbatim with 2 Peter 2, except Jude's writing really distinguishes between "people" and "angels" in the comparison of God dealing with falsity and pride.
But, I could be wrong.