Yes, if any view which contradicts what Jesus said about the Messiah is true, then what Jesus said about the Messiah cannot be true. That seems like a tautology.Elijah John wrote:
Perhaps Jesus and Christians, not Jews, are wrong about what the concept of Messiah means.
Read in context, Jesus words in in Matthew 16:28 were not about any kind of second coming.Elijah John wrote: It would not be the first time that "Jesus" was wrong. (see Matthew 16.28) He was wrong (or the Gospel Evangelists were wrong) about his 2nd coming occurring in the lifetime of his apostles. The "some standing here not tasting death" and all that.
Yes, Jews could be wrong as well regarding the expectation of King David's successor ushering in a Messianic age of universal peace, knowledge of God and the primacy of Israel among the Nations. But as far as I know, (unlike the Gospel Evangelists), they have not predicted when this would actually happen.
The Gospel Evangelists (yes, I know that phrase is redundant) record Jesus as explicitly saying that he did not know when the end would come. That makes it difficult to support the claim that they predicted when it would happen.