It was most likely just the 'virus du jour', the emerging virus at the time when black hat plan was put into action, if it had been another one that would have been the focus of the 'crisis'.
Doesn't matter much to black hats what they call it or the specifics of the virus they used, the 'pandemic' could have been any emerging virus and that was the likely plan and the one that makes the most sense, something that be taken and used to serve their plan regardless of any sudden/urgent changes in timing that a fluid situation might bring on.
it's just the smartest and most sensible/flexible way to plan something like this, to use what is already there whatever that may be….