>>12894505Seattle can more feasibly get an NBA team once again because the infrastructure is in place to accommodate one. The city now has an NHL team that can share the cost of building a new venue between them. This is why Vegas is in a good spot for the 31st or 32nd NBA team as well.
Football stadiums are a much bigger undertaking and it's hard to see a clear pathway for one to be built in a city that doesn't already have an NFL team. Raiders are in Vegas for good. Nashville is building a massive new complex for the Titans that will host a Super Bowl eventually. St. Louis is a sadly decaying city. Oakland has prime real estate but no political will. They're a city on the brink themselves. The NFL bean counters have probably figured out that the Bay Area can only support one team anymore. Austin is a possibility, but it's noticeable that the NFL has presence in Texas cities where college football is a secondary attraction. That's not the case in Austin.
Louisville has no major pro sports and their biggest sports draw (Louisville Cardinals basketball) has been kind of shit lately. However, they aren't that far from Nashville or Cincinnati, so an NFL team there would probably cause market oversaturation. Oklahoma City probably is the best domestic relocation option, but the NFL doesn't like to overlap with college football where it's firmly entrenched as the predominant sports fixture. There is a secondary concern with OKC being slightly more prone than other metros to natural disasters as well.