Going through the dialogue and screen text files reveals that several of the loyalty missions originally had very different plots:
"Bored with being the galaxy's top bounty hunter, Zaeed's also exhausted by up-and-comers seeking a rep written in his blood. Now he's learned that the second-best bounty hunter has gone corporate, and job one is to kill Zaeed. Zaeed's plan: wipe them out first... with extreme prejudice."
"You helped Zaeed fake his own death, and he's grateful."
"Kasumi revealed that Nava Corp has designed and is about to unleash tailored bio-viruses against the citizens of the Alliance. Only Nava Corp possesses the vaccines. Kasumi needs you to help stop Nava Corp permanently."