Joh 11:12 Then said his disciples, Lord, if he sleep, he shall do well.
Joh 11:13 Howbeit Jesus spake of his death: but they thought that he had spoken of taking of rest in sleep.
Joh 11:14 Then said Jesus unto them plainly, Lazarus is dead.
Yes, Lazarus was dead because Jesus had not yet been sacrificed.
On another note, Jesus met with Elijah and Moses, correct?
It appears that even those that died BEFORE Jesus's sacrifice were taken to Heaven. Of course, those were two exceptional servants of God. Still, it does demonstrate that there are exceptions.