Okay, time to get technical. Jewish animal sacrifices could only atone for sin, like covering it up. In no way could they totally forgive sin. So yes, the Jews still needed the sacrifice of Jesus, because only through Jesus can we have the complete forgiveness of our sins. Animal sacrifices only looked forward to the sacrifice of Christ, but they could not match the efficacy of the sacrifice of Christ.
So no, the Passover was much more than a recalling of the events of the flight from Egypt. Leviticus is quite clear about what the sacrifice is for:
Leviticus 17:11 For the life of the flesh is in the blood; and I have given it for you upon the altar to make atonement for your souls; for it is the blood that makes atonement, by reason of the life.
And Hebrews speaks much the same way:
Hebrews 9:6 These preparations having thus been made, the priests go continually into the outer tent, performing their ritual duties; 7 but into the second only the high priest goes, and he but once a year, and not without taking
blood which he offers for himself and for the errors of the people.
And it also explains why the blood of Christ is different:
Hebrews 9:13 For if the sprinkling of defiled persons with the blood of goats and bulls and with the ashes of a heifer sanctifies for the purification of the flesh, how much more shall the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify your conscience from dead works to serve the living God.
And makes it excruciatingly clear:
Hebrews 9:22 Indeed, under the law almost everything is purified with blood, and
without the shedding of blood there is no forgiveness of sins. For since the law has but a shadow of the good things to come instead of the true form of these realities, it can never, by the same sacrifices which are continually offered year after year, make perfect those who draw near. 2 Otherwise, would they not have ceased to be offered? If the worshipers had once been cleansed, they would no longer have any consciousness of sin. 3 But in these sacrifices there is a reminder of sin year after year. 4 For it is impossible that the blood of bulls and goats should take away sins.
And the point is thus: the Jews had to continually offer sacrifices of atonement because they were flawed. Only the sacrifice of Christ can forgive sins totally, and since the sacrifice was perfect, it was needed to only be completed once. We have total forgiveness of our sins through the one sacrifice of Christ.
So then what are we to do today? The author of Hebrews goes on to say:
Hebrews 12:28 Therefore let us be grateful for receiving a kingdom that cannot be shaken, and thus let us offer to God acceptable worship, with reverence and awe
And then makes an odd allusion:
Hebrews 13:10 We have an altar from which those who serve the tent have no right to eat.
We need to read this a little more closely.
NICK'S CATHOLIC BLOG: Habemus altare! - We have an Altar!
Where else is an altar mentioned? In 1 Corinthians 10?
Therefore, my beloved, shun the worship of idols. 15 I speak as to sensible men; judge for yourselves what I say. 16 The cup of blessing which we bless, is it not a participation[e] in the blood of Christ? The bread which we break, is it not a participation[f] in the body of Christ? 17 Because there is one bread, we who are many are one body, for we all partake of the one bread. 18 Consider the practice of Israel; are not those who eat the sacrifices partners in the altar? 19 What do I imply then? That food offered to idols is anything, or that an idol is anything? 20 No, I imply that what pagans sacrifice they offer to demons and not to God. I do not want you to be partners with demons.[g] 21 You cannot drink the cup of the Lord and the cup of demons. You cannot partake of the table of the Lord and the table of demons. 22 Shall we provoke the Lord to jealousy? Are we stronger than he?
Those who eat the sacrifice are partners in the altar. What do we do at the altar? We drink from the cup of blessing, we participate in the Blood of Christ. We eat the one bread, we participate in the Body of Christ. We have an altar, and from the altar we consume our sacrifice, which is Christ, offered for our behalf. Look at what St. Paul is saying. The Jews and even the pagans consume their sacrifices. Christ, the most perfect sacrifice, is also to be consumed. We have an altar, and upon that altar we recall the sacrifice of Christ offered once for all.