Is Jeff Probst Jewish

Answer 1

Yea

Answer 2

Yes.

Probst, the surname, has it's origins in the German (middle high german) "probest" and the Latin "Provost", and denotes a status or rank, that of a religious chapter -

The name "provost", and it's Anglo-Franco derivatives, in the middle ages were often used to denote Military rank or civil status,

a logical assumption is that it's Jewish adoption was used in order to denote status of a religious nature,

Clergy and affiliated persons to the Jewish religious establishment were often celibate and sometimes seen as self-important, so the adoption could possibly be as use for a nickname