Yes. Those are comparable.
Ontario has a conservative government, and the federal conservative party supported the convoy to some degree, and a few MPs met with truckers.
This would be similar to Democrats firing someone for donating to BLM.
Is there such precedent?
The Ontarian conservatives as far as I'm aware were always against it.
The crucial question, is this the party in power, or not.
In case of Oregon, this appears to be solidly Democrats, not Republicans.
In the incident described in the article, Ontario is governed by the Ontario Conservative Party, and so for the comparison to be valid, it would have to be against a governing party, in case of Oregon that to be Democrats.
Did any Democrat in Oregon fire any staffers, or similar, that donated to BLM? Militants that allied themselves with BLM have murdered people, which AFAIK is something far beyond anything truckers have done.
I have not heard about any donors to BLM being fired over that, and if such precedent exists but for some reason was not widely covered, please post examples, tia.