"Reveal" vs. "revelation" as nouns

Solution 1:

Reveal is used as a noun to mean a final revelation previously kept from the characters or viewers in a film or television show.

Solution 2:

Not only is it fine: it's in Oxford Dictionaries.

(In a film or television programme) A final revelation of information that has previously been kept from the characters or viewers:

The big reveal at the end of the movie answers all questions

Solution 3:

According to the OED this use of reveal as a noun was common until the 18th century, after that it was considered obsolete. But it came into use again with the predecessors of reality TV in the 1950s (think Candid Camera). I suspect it has gained in usage as an alternative to "revelation" because of the religious or connotations of the latter.

Solution 4:

Reveal is fine; in this context it is synonymous with revelation. Reveal is more commonly a verb than a noun, so this is probably a case of overcorrection; it's probably more common than alternatives like divulgence, for example.