In Samurai Cat, Cinderheart is the reincarnation of the witch doctor Cinderpelt. Is this true?

It’s true. When LZ asked why, was he asking why Cinderpelt was reincarnated? Taking into account the various books that have been translated into Chinese, here's why:

Cinderpelt was a cat who wasn't supposed to be a medicine cat, and Tigerclaw (Tigerstar) caused the disaster entirely by accident. StarClan was also frightened at that time. In fact, Cinderpelt and StarClan have no connection. See the second part to learn that Leafpaw (Leafpool) is a very spiritual medicine cat and gave Leafpool all the signs. Cinderpelt foresees the omen (Fire and Tiger), but she interprets it incorrectly, causing Firestar to become suspicious of Brambleclaw and Mousepaw (Squirrelflight). This suspicion was dispelled once the Clan cats found a new home. StarClan gave Cinderpelt a chance to repent, and they allowed Cinderpelt to live with her death date known, but Cinderpelt still lived optimistically, and she did not stop Leafpool from finding her own future (even though she knew that Leafpool If he left, ThunderClan would be without a medicine cat). So StarClan gave Cinderpelt a chance to be reborn and pursue her dream of being a warrior.

Also, the person above said that Firestar knew that Cinderpaw (Cinderheart) was the reincarnation of Cinderpelt, so he named her Cinderheart. This is absolutely wrong! The only ones known at the time were Leafpool and Jaypaw (Jayfeather). Firestar was named Cinderheart because Cinderpaw (Cinderheart) looks very similar to Cinderpelt, to commemorate his old friend.