You think they wouldn't still go hard at Jessie just because they learned Saul was also a huge, and bigger, part of the operation? That just made them go hard at Saul, it doesn't change a single thing about their pursuit and punishment of everyone else. By that logic they would not have cared about Saul this entire time because Walter White was already dead. If they catch Jessie and HE says the operation would not have worked without HIM, they wouldn't shorten Saul's sentence.