First of all, it is Gensler, so much should be discounted immediately. Second, if the SEC would approve a "physical bitcoin" ETF vs the futures based ones, many people who want to hold bitcoin would do it that way and "investment advisors" would be able to use the ETF. Third, perhaps some of the large players who are already custodians would just hold crypto, e.g. Fidelity, Vanguard, ML, Schwab etc.
People shouldn't be hold bitcoin on most of these new exchanges anyway and scammers may say they are segregating investor's bitcoins, but they'll find out later that they weren't.