It’s interesing that the company can just decide not to report this as a mass layoff. While the performance reasons for letting someone go may be true, it seems like an easily exploitable loophole. Model 3 production rates were missed by a wide margin, so at least a few people should have known that management would react.
Company's don't get to decide. It is written in law. Check the WARN act, but the key threshold seems to be 500 workers at a single facility. As an employer, getting rid of your worst 1% of workers once a year is just housekeeping.
The former is your fault as the employee, the latter is due to larger business conditions and generally recognized as no immediate fault of your own. In real world terms, you can be personally fired for not doing your job and can be laid off because the company can't afford to keep your plant/office/division running due to outside conditions.