If anything that paper looks really cool (not that I understand it). Transforming classical problems like graph isomorphism into a quantum algorithm is legit science and potentially extremely valuable.
I have my doubts...
Not sure what the key paper is, but "Graph isomorphism in quasipolynomial time" is at leas relevant:
https://dl.acm.org/doi/10.1145/2897518.2897542
or perhaps, this arxiv paper:
https://arxiv.org/abs/1512.03547
No idea about a quantum algorithm for GI