Yes, they were all wrong. Note that they all belong to
the soft sciences; mostly psychology (pop-psychology)
The one about eggs causing heart disease was guilt
by association, not actual experimental results.
Medical science news is full of correlation evidence,
nutrition science in particular, where correlation can be influenced
by confounders and is often wrong. The other factor is publication
bias for p<.05 results. If many studies study the same thing
and only one gets p<.05 that's the one that gets published and is
very likely only a chance result.
This happens very rarely in physics where discoveries require
p<.000001 with at least one replication.
Journalists often jump the gun. They are eager to report
something new and sometimes exaggerate its importance.
Don't know what can be done about that.
Anyway take medical news with a grain of salt and
psychology news with two grains of salt.
The bloke in the street can't know that though. Journals
need higher standards and journalists need higher
standards and the public needs better education.
It does however happen that even with best evidence
a conclusion can change when new information
emerges. Science is not dogma. It can and will change
when new information warrants it.