There doesn't need to be a popular riseup. Zhang Gaoli's enemies in the CCP now have some ammunition they can use to convince the people in the CCP who don't give a shit about Zhang Whoever that it's best to get rid of him. Then it's all up to how many true allies he has. (Probably not many, as a has-been.)
I've seen a lot of reporting on Peng Shuai's public appearances or lack thereof, but little on Zhang Gaoli's whereabouts. My guess is that he's under house arrest while the party leadership decides how to deal with him.
No CCP leader is untouchable; they're all reliant on the support of their allies to remain in power. If that support ever runs out, they quickly find themselves stripped of all titles, at the wrong end of a corruption investigation and risk getting executed in the end.