Spitballing here, but I think the destruction of the Cradle is directly linked to the wiped hosts the QA team finds. I have to wonder, what if the host-hardware is merely a terminal streaming the "program" from the Cradle? Would make sense with hosts being so lifelike. The hosts are basically 3D printed humans, apart from whatever is powering them. I find it hard to imagine that the control unit, being basically the only cybernetic part distinguishing a host from human could be able to store so much data and perform that level of simulation by itself.
A few other things;
1) What I can't quite jive though is Elsie's words and the practice of storing discontinued host bodies at the sub levels. Why bother with the cold storage, if the hosts "all live in there" meaning the Cradle servers? Unless that can be assumed to be a long con of Ford's, a preparation to grant him access to a high number of host units that no one really keeps track of.
2) I don't think Dolores is truly sentient, she is merely programmed by Ford to think herself so. Her entire plot line seems to be a diversion, pulling the response team's attention away from other events, namely whatever Bernard is up to.
3) Bernard is not sentient either, and I don't think it's him that's waking up from the Cradle access. If it's just Ford or something else, don't want to speculate yet. Interesting though that he seems to employ scorched earth tactics when under direct control of Ford's, destroying first the super-secret minilab, and I'm thinking he'll also be responsible for the Cradle getting blown to shit as well.
4) Maeve is sentient, and her "magic" is merely her using the admin level access to directly overriding the streamed Cradle simulation of the other hosts near her, as opposed using voice command like earlier. Have to question though, why didn't she try that fuckery with the Indians. Sure, they didn't respond to her voice commands in the previous episode, but then again, neither did the Shogun World hosts at first.
