Comment by froobius
I couldn't see any citations or references in that video or its description. It presents it as him solving the problem himself, but I'm sure other people have written about solving the Game of Life in reverse with SAT solvers prior to this...
Edit: here's a paper on it from 2006, https://link.springer.com/chapter/10.1007/978-3-540-76928-6_...
Garden of Eden[0] is a related concept where time-reversal comes up. Mentions NFAs, DFAs, backtracking and brute-force analysis. I see no mention of it but the latter was probably doing custom SAT implicitly, even if there was no access to our nice fast modern solvers.
[0]: https://en.wikipedia.org/wiki/Garden_of_Eden_(cellular_autom...