Why infeasible? cube20.org says "a good desktop PC" can optimally solve 0.36 random positions per second. And that's from the year 2010. I don't see why a web-based solver 16 years later should be much slower.
I'd say both weird and coincidental :-). I'm the author of that StackOverflow question and have nothing to do with that paper. As far as I understand arXiv (I'm not familiar with it), the paper was submitted to arXiv before the StackOverflow answer that inspired my question, and published by arXiv after my StackOverflow question: https://arxiv.org/list/cs.DS/recent
And apparently vcube optimally solved six cubes per second eight years ago already: https://github.com/Voltara/vcube