There are statements which are independent but not provably independent
If the independence of a statement is a meta-mathematical theorem, then the existence of statements which are independent but not provably independent is a meta-meta-mathematical theorem.
See the post: Are there statements that are undecidable but not provably undecidableAre there statements that are undecidable but not provably undecidable (undecidable is here synonymous of independent) and the positive answeranswer (under ZFC, assuming its consistence).