Pros
I would like to be able to write something positive, but I cannot. Being lied to, misled and investing time throughout the hiring process only to start a position and have job requirements added to the job description after starting is ultra shady. If you are hired for a certain position, with certain requirements, a company should not wait until after you start to modify said position/requirements. Even still the job posting remains on job sites with the original content, which leads me to believe something underhanded was done. Definitely seems like a walking HR/EEOC violation waiting to happen and I would avoid wasting your time on a company that condones this.
Kontras
One would think that a company would use the 2-3 weeks worth of interviews/paperwork to vet new hires and ensure they are hiring the correct person for the correct position. I have never seen such a backhanded practice in all my years of working for the Federal Government/Private Sector. With practices like this, I'm glad to have not invested more time and energy in working for a company that treats it's employees in such a fashion.