In fairness, these newer fans would have never experienced the intensity of the rivalries with Chester, Cardiff and Swansea. They don't get the geography and history of their newly adopted club. The fan culture in the USA is v different too and the closest thing their have to the intensity of rivalries in the UK is their college football teams.
Even then, their rivalries are more Liverpool v Everton (i.e. friendlier affairs) than Blackburn and Burnley (two towns that hate each other without knowing why).
I'm glad our fanbase hasn't been mobbed like that. For the most part, our 'growth' has been pulling in locals who used to support the likes of Man U, Liverpool, Chelsea and so on. I see a lot of people on social media who are 'diehard' Cov fans who at school, were 'diehards' for Prem teams.