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That is likely a Blooper more than anything. The shirt is probably for the originsl real-life movie, not a meta-comment on the current movie world.
Yeah, I'd call this Cowboy BeBop at His Computer for the video calling this a continuity error. It's made clear that this was an incredibly rare item because the original park was never opened and this shirt was unsold merch that somebody found in a warehouse or something and put on ebay.
They're also ignoring that while a coverup was attempted, it was of the Surprisingly Realistic Outcome sort: InGen obscured the details like the body count and how extensive the project was, but in-universe a ton of people still knew there was a first park that went bad. Ian Malcolm apparently ignored his NDA and went out of his way to denounce InGen at every opportunity, we see Dr. Grant frustrated at people showing up to his paleontology lectures to ask about the park instead of his research, etc.
Edited by Scorpion451

Is there a trope for when a character knows something that they canonically shouldn't know, and even the writers missed it?
The only example I have was brought to my attention in a fact fiend video about Jurassic Park. They briefly mentioned that a guy in Jurassic World wore a Jurassic Park shirt and praised the original park, despite the fact that the original park was canonically never opened, never released merch, and was covered up by the government.
This is different from metagaming or similar tropes in that this knowledge is in no way beneficial to anyone, and the guy who had it was not exhibiting an intentional fourth wall break.