The premise of Parler directly contravenes the AWS AUP, which demands that companies ensure their users comply with AWS's AUP and that companies kick users that don't. The whole point of Parler is to host Twitter users who violate Twitter's TOS, which is a cohort significantly comprised of people who are also violating AWS's TOS.
To believe that Parler would have been viable on AWS to begin with, they had to actively avoid reading the AWS terms of service. And, I mean, I'm sure they didn't, just like they apparently didn't authorize anonymous HTTP requests for their users assets. The whole effort seems clownish and performative.
In that light, I think I object to the notion of a "digital death sentence". They chose an incompatible provider for the services that they needed, and suffered the consequences. Gab, a service that is objectively far worse than Parler, appears to be doing just fine; in fact, they went through something similar to this after the Tree of Life shooting was planned on their service, and Parler had to have not paid any attention whatsoever to what happened to their most important competitor to have believed they had a chance on AWS.