I think it's definitely justified in the sense that it's understandable to strike back, but it's hard to take a moral high ground now.
I don't think the moral high ground means much in geopolitics. Power is way more important. "Better not curtail us, it'll make you seem mean..." This is the US we're talking about, known around the world for turning half the middle east into a desert. That's really not their primary concern.
For example, I don't think the trade war did damage relations with Canada - if what you're measuring is tangible results, rather than sentiment. From what I can tell, the US basically said, "give us a better deal, now. Also we're boycotting China." Canada said "I don't want to. But OK," and then... Nothing else changed. The US won, and Canada didn't reprimand them. Results > sentiment.
Forcing Canada to choose between the US and China is absolutely a strategic option for the US, and possibly an important move to make given how heavily China is invested in Canadian property. America doesn't want China getting a foothold on their continent. Even if it pissed off the Canadian public... So what? What are the practical results?
Note the US is currently embroiled in similar situations with Britain (Assange & the Hit & Run Diplomat). They practically forced the UK to join the war in Iraq, which pissed the UK public off way more than Weng Menzhou - doesn't matter. They won, & the UK is still a (staunch) ally.
Favorability is down double digits from 2018 in APAC (though strangely up double digits in parts of europe).
So "only china believes china's narrative" isn't super technically correct but I think the general sentiment is accurate.
https://www.pewresearch.org/global/2019/12/05/attitudes-towa...
Why do I say so?
1. The justification for this is that it's a "national emergency with respect to the information and communications technology and services supply chain". Supply chain? Are you kidding me? The permissions given to the executive to declare emergencies for critical goods and services such as related to war time -- these extend to a voluntary communications app? Strains belief, and however you feel, this is not a good precedent to allow.
2. CCP is censoring / monitoring / scraping users' data, so this is a national emergency.... but not for 45 days and then also ok if we can buy the company on our terms.
This is yet another thing I guess time to throw up your hands and say, this is how we live now. One throw-it-against-the-wall proclamation after another.
Even if you're somewhat ok with it, are you really ok with this principle being applied, when someday it may not go how you want, for something you care about?