Canaan never symbolizes heaven in the Bible. Maybe in some hymns but never in the Bible. There were giants in Canaan- there are no giants in heaven. There were battles to be fought in Canaan- there will be no battles in heaven. God’s people sinned in Canaan- in heaven all traces of sin will be erased.
Canaan represents the fullness of salvation, the fullness of blessing, the possessing of our possessions. Canaan was what God redeemed Israel for, just as victory is what God saved us for. He brought us out of sin so that He might bring us into the abundant life. Many Christians are out but not in. They are like those spoken in 1 Corinthians 10:5-“ Nevertheless, with most of them God was not well-pleased; for they were laid low in the wilderness.”