No. She's supposed to have said she won't fight the next election. That's not quite the same thing. And besides, nobody in her party believes a single thing that comes out of her mouth any more.
And regardless of who steps up, they have the same problem. A remainer and you have a continuation of the same issue people have with her. A Brexiteer (which is certainly what the membership would vote for) and that person is at odds with their parliamentary party. Add to that the very real anger among many, many Tory voters over their handling of Brexit and the possibility of a Brexit party of protest and I'm just not sure the Tory party is in any position to fight an election right now.
And actually, Corbyn's lot have played Brexit pretty well. They've played both ends against the middle such that they can claim to be both the voice of reason and consensus in delivering a soft Brexit (thus keeping all but their most rabid remain voters onboard) while not being seen to betray the wishes of their Leave-voting heartlands. Everything else they say and believe is a reason not to vote for them, but on Brexit they look likely to escape with a certain amount of credit and (more crucially) none of the blame.