>the sole source of information is a twitter thread from "Hector"[0].

Mate, Marcan is not just some guy called Hector.

He's one of the most respected guys from the homebrew scene, and semi-(in)famous in electrical engineering circles too!

Not saying the thread is true, but the guy sharing it isn't a nobody.

There is no evidence aside from a Twitter image, and heresay with no records.

What records would you expect there to be that aren't there?

You seem to have no idea how obituaries work, you usually have to pay a newspaper to carry them, they aren't automatic, and if the news is published widely enough in the relevant communities why would you bother to pay for it? As for government records, vital records are often limited to people with an interest, such as family members, they aren't usually offered to the public. And why would such a person publish that record online? You might as well be claiming David Bowie didn't really die, I've never seen his death certificate.

Obituaries aren't official records, they're media statements. The official records are kept in a civil registry, which usually isn't open to the public until X years have passed (obviously this differs by nation; in NL, death records don't become public until after 50 years).