Definitely ample-grounds for speculation which I'll personally stay out of, but the phenomenon is a major puzzle in astrophysics right now. This is just another progression in our means to detect it.
The three bursts 1ms apart don't appear to be natural (or at least, we don't currently understand how they may occur naturally). The signal may be extraterrestrial.
If it is from a three-stage nuke it might be terrestrial. IIRC nukes have a characteristic double-pulse 1ms apart.