Yes, it is surprising. As I mentioned, 0.4% chance of death for a 45 year old man from all causes. That's surprising. Unexplained rapid onset respiratory disease to MRSA to dead is also surprising.
More evidence is needed - that depends what you mean. Needed for what? Conviction? Arrest? Sure. Suspicion and investigation? No.
Thing is... This isn't "all causes," nor is a 45-year-old aerospace employee a perfectly-spherical unit human. Adjust the Bayesian priors.
I've had relatives who worked in manufacturing. Note the past-tense. The things it can do to a person's respiration and cardiovascular system are... Not pretty. Especially if, say, they were working for a company with a history of dodgy behavior (because if they're putting product out to paying customers that sucks, are they really providing their front-line crew all the PPE that is required to keep them healthy?).
So a 45-year-old who put 20 years in at a place that, let's hypothesize, isn't controlling for silica dust the way OSHA demands, gets a flu during flu season, and down they go? Especially when we don't yet know what the long-term effects of exposure to COVID are (even with vaccination)?
Too many variables to be suspicious of direct malice. But, probably enough to warrant OSHA making a snap inspection of Spirit to count the respirators and check the filter expiration dates...
More evidence is needed - that depends what you mean. Needed for what? Conviction? Arrest? Sure. Suspicion and investigation? No.