This is a nonsense argument. It is possible that constantly making apocalyptic statements can result in an apocalypse, and saying that people should stop doing that is not contradictory.
The words you use matter. If trump is an existential threat to democracy, he should be assassinated. If you're not advocating for murderous escalation, then stop using those words (for example).
Who/what is defining assassination as a reasonable response to that threat, who/what maintains the list of words which can replace "democracy" in that section, and what happens when someone disagrees with the maintainer of that list?
You can "educate" someone all you want, they will still suffer from all the normal biases and those biases will still affect their choices.
This is why we have double blind trials even though doctors are "experts"
I do believe education on how to effectively engage against an idea which feels threatening is better equipped to handle this apparent fact than bigstrat2003's approach of teaching people to not say certain beliefs because they'd be worth killing about. That doesn't mean it results in a perfect world though. Some may perhaps even agree with both approaches at the same time, but I think the implication from teaching the silencing of certain beliefs from being said for fear they are worth assassinating over if believed true ends up driving the very problem it sets out against. Especially once you add in malicious actors (internal or external).
At the same time, I do believe there are ways to share such statements while also reinforcing healthy ways to react at the same time. kryogen1c's example ending in "he should be assassinated" crosses the line from bigstrat2003's talk of apocalyptic claims to direct calls to violence about them - the latter of which I agree is bad teaching (but I'd still rather people be encouraged to openly talk about those kinds of statements too, rather than be directly pressured to internalize or echo chamber them).
This is why the first question posed about the statement from kryogen1c was "Who/what is defining assassination as a reasonable response to that threat". The follow on questions were only added to help highlight there is no reasonable answer to that question because it's the call to assassination which is inherently problematic, not the claim someone is a threat to the democracy here. The latter (talking about perceived threats) is good, if not best, to talk about directly and openly. It's the former (calling for assassination about it) which is inherently incompatible with a stable society.