Yeah, I disagree, too. I think his general point is that in any form of hydro changes can happen quickly, whereas in soil they change slowly. I think that's a positive, though, as if a plant is sick you can quickly fix it rather than wait for a top dress to break down or have to brew teas.
However, all that is moot because he's in soil. Gaia Green Living Soil contains: peat moss, perlite, coconut coir, fir bark, composted porcine litter, African night crawler worm castings, glacial rock dust, dolomite lime, feather meal, alfalfa meal, bone meal, rock phosphate, blood meal, fishbone meal, mineralized phosphate, insect frass, mined potassium sulphate, basalt rock dust, humic acid, gypsum, kelp meal, oyster shell flour, greensand.
That said, I think most people amend right off the bat, as the potting mix can only sustain a plant for a couple of weeks. I don't do organic, so I'm guessing here that the remedy is to top dress with more living soil (maybe with some additional worm castings) until transplant, in which case more soil with castings and 4-4-4 would be added.
OP, did you water until runoff? If you did, you'll push out the nutrients from the soil and it will need to be reamended sooner. Watering until runoff is for when using bottled nutrients to push out the salts.
If you don't get any responses from organic guys, then watch Canucks Grow stuff for living soil. He goes into what he uses at about 5:30 in this video, which is Gaia Green Living Soil with 20% worm castings right from germination: