Hi sjames, welcome to the forum
That method is still the one to use
There are two schools of thought about plants.
The first is to plant the tank and wait two or three weeks to make sure the plants are growing well. Then start the cycle. But because plants use ammonia as fertiliser, you may see a drop in ammonia but no nitrite being made, or only a small amount. This will make the cycle different from the pinned one, but try to follow it as closely as possible. The main point to look for is the day you can add 3 ppm ammonia and have no ammonia or nitrite 24 hours later.
Plants also have filter bacteria in the biofilm covering the plant, so they can seed the cycle. But it needs a lot of plants to have any significant impact.
The second school of thought says to do the cycle, then add the plants. The reasoning here is that if you cycle with plants you won't grow as many bacteria because the plants will take up some of the added ammonia. If the plants then die, there won't be enough bacteria to remove the ammonia that would have been taken up by the dead plants. People who support this method reckon it is safer to grow all the bacteria needed for 3 ppm ammonia then plant the tank so that if the plants die there will be enough bacteria.
Also, some plants are sensitive to the amount of ammonia used during cycling and could suffer.
It comes down to - how good are your plant growing skills? If this is the first planted tank, I would use the second approach, cycle the tank than add plants. Should you decide to get another tank, you will know about your plant growing skills and can use the first approach for this potential second tank.