This is specifically about a consumer targeted carbon tax
There's a good case this should be lower, but often political leaders say one thing while trying to get elected and do another once elected, climate is a weak point for the Conservatives (in terms of there being wide public support for action on climate change, but the party being out of step with the public on that) so making big moves opens them to attack on that front, and lots of businesses would prefer policy stability to policy instability for investment purposes, and expect that if the Conservatives remove the carbon tax, the next party in power would just put it back. Even though there isn't unity among Conservatives around climate change, facts are facts and the people leading the party are likely to be aware that repealing climate change measures as the planet warms is going to be held against them longer term. I think Pollievre is politically smart enough to navigate that mess of conflicting pressures in a way that doesn't "almost guarantee" a repeal of the carbon tax. I'd say something he could call a repeal but provides stability and continuity in terms of its actual effects, and he can later say his government's plan reduced emissions while fulfilling his promise to axe the tax, is not unlikely, though, which will make market resolution tricky if it happens.