Does the hypothalamus control the hormonal secretions of the pituitary gland?
Yes and very much. Hypothalamus itself secretes neurohormones.
Hypothalamic neurohumors/neurohormones control secretion of anterior pituitary hormones, while posterior pituitary hormones are secreted directly by hypothalamic neurons. The hypothalamic neurohumors are known as releasing hormones, these are brought to anterior pituitary by a portal connection.