The open source for games usually only gets released once it has been succeeded by a sequel or enough time has passed to where it has a small player base due to lack of interest, so I doubt it. They were gonna release it when Among Us 2 came out due to all the bad coding, so others could mod it or host their own servers when it shut down. Now that is no longer needed.
I think it would have been interesting to hear their new position toward open sourcing the Among Us 1. I appreciate that cancelling the sequel also cancels the plan to open source Among Us 1, but since they showed interest in open source in the first annoucement, it would have been nice to have a few words about it.
Also, the code source could be open source and the assets closed. This could be a viable business model.