Exodus 12

 Concerning the Passover, the Lord instructed the Israelites - 

"...ye shall observe this thing for an ordinance to thee and to thy sons for ever."  (Exodus 12:24)

President Joseph Fielding Smith taught - 

“The Feast of the Passover was fulfilled in that form in the crucifixion of Jesus Christ. The Passover was a law given to Israel that was to continue until Christ, and was to remind the children of Israel of the coming of Christ who would become the sacrificial Lamb. After he was crucified the law was changed by the Savior himself, and from that time forth the law of the sacrament was instituted. We now observe the law of the sacrament instead of the Passover because the Passover was consummated in full by the death of Jesus Christ. It was a custom looking forward to the coming of Christ and his crucifixion and the lamb symbolized his death…. “The word forever used in the Old Testament does not necessarily mean to the end of time but to the end of a period” (Smith, Answers to Gospel Questions, 5: 153– 54).

Everything related to the law of Moses was looking forward to that great and last sacrifice.  This would also suggest that those that the Nephites honored the passover.