If a person is genuinely saved, they will observe the NT Passover at the time the Bible commands it to be done. That being said, it should be a requirement because Christ said it is a requirement:
"Then Jesus said to them, “Most assuredly, I say to you, unless you eat the flesh of the Son of Man and drink His blood, you have no life in you." - Jhn 6:53
“Whoever eats My flesh and drinks My blood has eternal life, and I will raise him up at the last day." - Jhn 6:54
“He who eats My flesh and drinks My blood abides in Me, and I in him." - Jhn 6:56
Note the 3 extremely important things Christ says in those passages:
1) A person who does not observe the NT Passover as commanded does not have eternal life in them and will not be one of the people who are resurrected at Christ's return.
2) Whoever observes the NT Passover as commanded has eternal life, and they will be part of that resurrection.
3)Whoever observes the NT Passover as commanded abides in Christ and vice versa.
A person cannot truly value or understand Christ's sacrifice if they don't observe the NT Passover as commanded. A lot of "Christians" use His sacrifice as justification for living in opposition to God's commandments and laws because they lack the understanding and appreciation that comes with observing the NT Passover. It may seem like a small issue to a lot of people, but it is one of the things that separates the people who will be at Christ's side when He returns from the people who won't.