Correct me if I'm wrong, but my understanding is that the reason people are convinced Nike will have something to do with the naming rights of the stadium is because of their NFL involvement? Well their deal with the NFL only runs to 2019, and could quite easily be replaced by Under Armour after that, so not sure we should be so confident that long term this will happen.
Something that might make it even more likely that Nike won't continue with the NFL post 2019 is that they're due to start an 8 year contract to supply NBA uniforms, at the cost of approx £1bn. With that in mind, would they also splash out a similar figure for the NFL again? If not then there goes our link to what we think will be a big revenue stream