So basically, they just want to earn from their clients buying Bitcoin without actually holding any Bitcoin themselves.
Honestly, it might be better for clients to just buy directly from exchanges and learn how to secure their assets properly. Banks aren’t really that helpful when it comes to Bitcoin investing. All they do is act as a bridge for traceable transactions and once that’s done, they collect their fees and call it a day.

This is just another ETF thing..
JPMorgan will offer clients access to Bitcoin exchange-traded funds (ETFs)
Jamie dimon is not for bitcoin is just in for business, since he have seen the massive growth of bitcoin and the massive adoption of bitcoin, he now decide to tap the glory of bitcoin by allowing his clients to buying bitcoin from his bank, so that his business will grow well goodluck to him, but my own opinion I we suggest that everyone should buy bitcoin directly from exchange and store their bitcoin by themselves instead of buying bitcoin from unbelievers banks like the person of Jamie dimon who have called bitcoin a scam before.
I think I love your perspective on been self custody which provides more control and security over your digital assets, just you have mention I think Jamie Doimons in past use to criticise bitcoin and also JPMorgan's has chase is now exploring ways to offer bitcoin services to it clients.