Appen Project Arrow Positions Filled

I successfully passed the qualification exam for Project Arrow on Appen. I was invited to work. But then the project disappeared from my dashboard all of a sudden. I emailed the support and they were like:-

"Due to the tremendous response, we regret to inform you that the position has already been filled for the Arrow project. Don't worry as you will be placed on a list to be contacted as soon as the opportunity opens again.

These positions open frequently, and we prioritize candidates for future opportunities that have already confirmed interest. "

I am just worried if I have to give the qualification exam all over again when a position opens up? Has this happened to someone? I wasn't even able to sign the documents for confirming my position.

Any insight on this would be appreciated. Thanks in advance.