The Temple sacrifices, Including the Passover will be kept during the Millennium.

Ezekiel's Temple, This Temple has not been built yet

Ezekiel 45:21
In the first month, in the fourteenth day of the month, ye shall have the passover, a feast of seven days; unleavened bread shall be eaten.

22 And upon that day shall the prince prepare for himself and for all the people of the land a bullock for a sin offering.

In memorial looking Back to when YESHUA became the Passover Lamb

Without a Temple and Priests to offer the sacrifices, not required at this time, when Judah was in the babylonian exile, there wasn't a Temple and Did the Torah vanish then? No, but were temporarily put on hold for 70 years.