Maybe. All the retail banks I know don’t start true private banking until there. For example, here is an article about JPM requiring 10 back in 2016 (it’s higher now): https://www.wsj.com/articles/at-j-p-morgan-9-million-in-asse...
The non retail banks that have a good reputation are even higher.
They don’t outwardly advertise their minimums because “it depends.” For example if you’re an up and comer in your field where it seems like you’re LIKELY to one day hit the mins, they’ll start the relationship early.