Yes, the seven feasts are definitely rich with prophetic meaning. But I would say that for the Day of Atonement, both goats represent Christ. He died and He also took our sins far away. I don't think Satan is the scapegoat.
As for the feast of Tabernacles, yes, it seems to represent the Millennium, as we see this celebrated in Zechariah 14:16.
But Paul also said this:
Colossians 2:16 (ESV) Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. 17 These are a shadow of the things to come, but the substance belongs to Christ.
As for the feast of Tabernacles, yes, it seems to represent the Millennium, as we see this celebrated in Zechariah 14:16.
But Paul also said this:
Colossians 2:16 (ESV) Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. 17 These are a shadow of the things to come, but the substance belongs to Christ.
Lev 16:10 But the goat, on which the lot fell to be the scapegoat, shall be presented alive before the LORD, to make an atonement with him, and to let him go for a scapegoat into the wilderness.
Lev 16:21 And Aaron shall lay both his hands upon the head of the live goat, and confess over him all the iniquities of the children of Israel, and all their transgressions in all their sins, putting them upon the head of the goat, and shall send him away by the hand of a fit man into the wilderness:
Lev 16:22 And the goat shall bear upon him all their iniquities unto a land not inhabited: and he shall let go the goat in the wilderness.
This goat represents Satan who bears the responsibility for introducing sin in the garden and deceiving mankind leading them in to sin and death.
Rev 20:10 And the devil that deceived them was cast into the lake of fire and brimstone, where the beast and the false prophet are, and shall be tormented day and night for ever and ever.
Jesus Christ DIED for our sins to pay the penalty of death for sin.
Rom 6:23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
The Azazel goat (scapegoat) was turned out into the wilderness alive. The scriptures plainly show that Christ died for our sins. Yes, the Azazel is the pictures the Devil being cast into the bottomless pit.