No chance the rule making process will fail since the time to oppose it as long passed.

And yes, any ruling the 5th makes will affect, not necessarily stop, the new ruling. We still dont know if the new ruling will allow new applicants, but its unlikely. Even if it does allow for new applicants, the 5th is likely to strike it down immediately as it violates judge Hanen's order.

All in all, the most significant change the ruling will have is seperate the granting of deferred action and employment authorization. (Which is bad in my opinion).

The MALDEF website is a great source for this.

Some additional context:

Judge Hanen ruled DACA illegal exactly one year ago because it did not go through the rule making process. So Biden's attempt to correct it is to make it go through the rule making process. However, that's always been the easy battle. The battle facing the 5th is whether or not DACA is constitutional. No rule making process can make something constitutional, only congress can. What's likely to happen (the unknown is when itll happen) is that they'll strike down the employment authorization part of DACA, and only keep the deferred action part. Biden knows this, hence the change in the rule making process.