Theoretically speaking, SE would need to have negotiated with FAF to allow vault content owners to "hand off" their contributions to FAF, and therefore the company. This either takes form in how you upload content to the vault, be-it an ammendment to the terms and conditions you accept upon uploading, or perhaps one would need to "submit" your content for validation by an internal SE QA team before it's accepted.
Theoretically speaking, you wanted to create a career for yourself out of making the same content you uploaded to the vault.
Demonstrating that you were able to "hand-off" your work(s) to a large name buisness looks very nice on an application.
So yes, I would be fine with that.
The only way I see SE using that agreement is to capitalise on FAF if it were to "magically" implode in popularity. I dont see that implosion happening, so it's a null change.