That's what's?

[ucul]

I keep hearing my native English (AmE) speaker friends says:
1. That's what's in the album.
2. That's what's important.
3. etc

My question is, is that grammatically correct to say "That's what's..."?

 

[Matthew Wai]

I think it is grammatical because the what-clause functions as a noun, the predicate noun of the sentence.

 

[emsr2d2]

It's fine. That's what's important = That is what is important = That is the thing that is important.