Claiming it was coincidental is hardly an answer for the crews who have stay safe on the high seas. There could be a coincidence that all the upgrades might have been done by the same contractor installing the same equipment on similar frigates based in Esquimalt.
They will tell us the truth once they have finished with their investigation of the fire in Protecteur!
If these fires really occurred as they claim, they would be looking for similar problems with other ships in the same class and for safety reasons likely taking them out of service while that happened. If they don't do that work as a precaution, then it tells you that they are probably not telling us the truth.