Abraham had been concerned that Isaac should not marry a Canaanite, and now Isaac didn’t want his sons marrying the Canaanite women.
This probably made it easy for Isaac to agree to send Jacob away so he couldn’t find a Canaanite woman to marry, even if Rebekah’s motive was to keep Jacob safe from a vengeful Esau.
But it was only when this happened that Esau realised he might not have been wise when he married two Hittite women from Canaan some years earlier, when he had turned 40 (Genesis 26:34):
Genesis 28:8–9 It was now very clear to Esau that his father did not like the local Canaanite women. So Esau visited his uncle Ishmael’s family and married one of Ishmael’s daughters, in addition to the wives he already had.