1 Corinthians 5:7 Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:
No. I suspect that they were both speaking of leaven in the same sense that the Jews did (and it was the same reason that the leaven was left out of the Passover Seder as well). And yet the Passover feast was still a real feast, no? The leavening (our sin I believe) was left out. But it was left out of real bread as well, not just metaphorically. How does your point change the tie between Passover and Easter? The verse is still "Christ: Our Passover Lamb"