Can we use gravitational waves to rule out extra dimensions – and string theory with it?

Gravitational Waves, Computer simulation.
Credits: Henze, NASA

Tl;dr: Probably not.

Last week I learned from New Scientist that “Gravitational waves could show hints of extra dimensions.” The article is about a paper which recently appeared on the arxiv:
Signatures of extra dimensions in gravitational waves
David Andriot and Gustavo Lucena Gómez

arXiv:1704.07392 [hep-th]

The claim in this