The monarchy does represent historic injustices and the last opinion poll noted that a majority of Canadians want the oath to the monarchy to be removed (link below). So it would seem that this historic anomaly is incompatible with prevailing public opinion and indeed the Canadian charter and our commitment to Indigenous reconciliation. In other words, it's un-Canadian.
You're aware that there are other interpretations, right? Have you read about those?
I mean, you can
choose to go with your interpretation, but you can also choose to listen to other interpretations and go with the ones that fit your values. And where things don't - commit to change them as a citizen of a free society. (Because of course no single interpretation is correct in all senses, and Canada - like other societies - is a mass of contradictions and anachronisms, too).
One interpretation - for example - is that since the Magna Carta, the history of the monarchy has been one of 'the people' - slowly - asserting its rights and consent to govern and be governed (simultaneously), by means of representative democracy. Initially, by imposing limits on the power of the monarch and eventually wresting that power away, reducing the role of that monarchy to a primarily symbolic one, with some residual powers , and even those residual powers can be taken and stripped away at any time. And that this happened by evolution over time, with each generation adding and changing some aspects.
I'd also add that in the Canadian context, even though we were different colonies, the history didn't start or end in 1867, with responsible government / home rule years before that - 'independence' was not granted nor simply taken, but a mix of the two.
I don't think that mix is 'un-Canadian' at all.
And neither do I think this is incompatible with indigenous reconciliation or public opinion. Public opinion can xpress what it doesn't like, but anti-monarchist sentiment falls apart on the slightest prodding with the question "replace it with what, exactly?" - as there is absolutely no consensus on that (and it's quite Canadian to be a bit cautious or conservative about jettisoning a system that mostly works).
On indigenous reconciliation: I'm guessing you're not one, and I for one would be cautious about speaking for them on the topic. The indigenous people I know don't have monolithic views on the monarchy either.
Up to you to decide though of course. If you can't get to a version of it all that makes you comfortable with swearing the oath - then don't. Canada will be a little worse off for it, and the rest is your own affair.