My thoughts
1. I'm going to take anything Avenatti says with face value a grain of salt as he's facing extortion and fraud charges that if convicted could potentially land him in prison for the rest of his life
2. It suggests that Nike "offered" Langford $20k. Offered doesn't mean accepted. I'd be willing to wage that most recruits in the top 10 or 20 of their class going back the last 20-25 years have been "offered" something by some sort of third party agency to attend a school. I've seen a post that suggests if Nike was offering $20k, "how much was Adidas offering for him to end up at an Adidas school?"
3. To end my thought on #2, there was just a 2 year investigation and trial that recently concluded that ended with convictions for multiple people involved with Adidas. There was hours of testimony and thousands and thousands of documents entered into the courts, none of which suggested Adidas was in a bidding war with Nike to secure a commitment for Romeo Langford. There were however, other individuals named. Nike very well may have "offered" Langford, it doesn't mean he took it.
As far as where IU stands in all of this? Why would IU (an Adidas school) being working with Nike to secure a commitment for Romeo Langford.