She kinda has to... But there are loopholes.

(In case you can't tell... I consider the Brothers in RWBY to be absolute pricks.)

"Alright... But I want your words, binding, that you will not destroy Remnant, OR its people if I abide by those terms."

"Are you calling us liars?" The Elder asked, tilting his head.

"No, but no God or Goddess worth their salt makes any kind of arrangement with other deities without making it binding. A lot of us are petty as hell," she replied, mentally adding, 'You two included.'

"Very well, you have our words, if you give us yours as a Goddess that you will abide by your terms, or leave should you break them," the Younger added.

"Alright, you have my word as a Goddess," she replied, briefly glowing as she was bound to her word.

The Brothers gave their own, and she found herself back on Remnant where she had been before being so rudely yoinked out. And she smirked. It was almost too easy to leave herself a loophole... Sure, she had to give Salem and her subordinates at least temporary immunity to Jaune's Note... But, that didn't include some individuals who worked for said subordinates instead of Salem herself.

She'd stick to the letter of the agreement... And all the while stomp gleefully all over the spirit of it as they were bound to do nothing but rage upon realizing they'd been had.

And the best part? That didn't even scratch the surface of just how badly she had played them.

(Yup, Ria just played the Brothers for fools. This is hardly her first rodeo after all. This means Emerald and Neo are still on the table for Jaune, even though the Brothers had intended them to be included in the immunity clause.)