That's not a particularly complex way of looking at it. the nuclear plant is a base load plant, meaning you can pretty much just subtract its output from the predicted consumption, and then you can simply have less renewable energy, load peaking is midday anyway, which is when solar is productive. (or have less energy storage, since the nuclear plant will combat that), you would have a more consistent and regular power production at that point, and waste less money. (since you aren't burning money on running a nuclear plant at a reduced/no output, you would technically be burning solar energy (you cant burn wind energy, you just stop the turbine, and it wont produce power) but that's cheaper anyway, and besides beyond install costs, very low continual maintenance)

Though if you were going to shutdown the nuclear plant at its EOL then you would need to increase production of renewables, which is easy enough. Saying that "nuclear and solar/wind don't mix" is just kind of weird. Realistically the only better mix would be solar/wind and gas since gas can manage peak loads super trivially, which is of course not very green. So arguably nuclear would be your ideal match unless you went explicitly solar/wind.