Yes. It must be said that an angel could not of his own will be turned to beatitude, except by the help of grace, because if there is anything which is above nature, the will cannot be inclined towards it, unless helped by some other supernatural principle.
To see God in His essence, wherein the ultimate beatitude of the rational creature consists, is beyond the nature of every created intellect (Q12, AA4-5). Consequently no rational creature can have the movement of the will directed towards such beatitude, except it be moved thereto by a supernatural agent. This is what we call the help of grace.