I thought he was planning to use the Square Kilometre Array radio telescope which is still in the works, and not to be confused with the Ice Cube neutrino detector which has been operational for several years.

https://cdr.skatelescope.org/

https://icecube.wisc.edu/science/icecube/detector

Then we'll find out when it comes online! If the new theory is compatible with past observations, and correctly predicts something that GR gets wrong, that will be a huge finding! But the press has gone wild prematurely, as they often do. As others have mentioned, that seems to be the real issue to which Dr. Hossenfelder objects.