Or maybe they would allow new scams to emerge, because in the grand scheme of things crypto is insignificant. All these billion dollar marketcaps are imaginary, there might be very little actual money going into altcoins, so there's very little point in regulating it. So, if exchanges will become regulated and not allowed to list tokens without approval, scammers will move to smart contracts and DEX's.
I'm sure they'll find a way to sneak around but it won't happen again out in the open. The SEC is slowly wiping out as many people as they can get their hands on.
Nothing'll stop it on the fringes of course but there'll be a time when these tokens or any equivalent outlet won't be allowed on any exchange that wants access to major markets. If your piece of shit can't bribe its way into somewhere with volume it suddenly becomes a lot less tempting to potential victims.