The price of renewables scale down as demand rises, and the capacity we have building them is growing at an exponential rate at least somewhat capped by demand. It follows that if you want to displace existing power sources, you're probably better off driving demand up, because that lowers their price and makes replacement more economically attractive.
As long as you're not driving demand up faster than the industry is able to increase its rate of scaling (which doesn't yet seem the case with AI, though that's not to say it couldn't be at some point), this should help a renewable transition.
Another effect is that you push issues that arise in transition earlier. For example, the sooner you have a lot of solar on the grid, the sooner grid-scale batteries are incentivized, and the sooner battery production scales. This feeds back into the feasibility and profitability of replacing existing nonrenewable sources.
A simple example where this effect is very clear is synthetic fuels. Synthetics don't compete on a dollar-for-dollar basis yet, but from an energy basis they're getting close. There's an obvious demand phase change once you hit that price point, and the sooner you hit it the better. If you believe the scaling trends, and I think you broadly should, more solar brings that point forward and so is clearly environmentally beneficial.