Honestly - this "seasoning" process sounds a lot like the "breaking in" a speaker process I've read oh so much about in car audio circles.
Something dreampt up by sales people/shop owners designed to BS an unsatisfied customer into not demanding a refund.
Dump an ice cube into a glass of warm water. Look at what happens. The structure of an ice cube is unstable, and will expand at different rates internally. When you introduce a large temperature differential, different parts of the cube expand at different rates, and the cube - being unable to contain the stresses - cracks.
A brake rotor works in the same way, and the crystalline structure of an iron rotor looks surprisingly similar to one of an ice cube. The same physics applies; if you heat a fresh rotor up too fast, the different parts of the rotor will expand at different rates. Iron, being more ductile than ice, will simply warp, but if it heats up too fast, it can and will crack.
Now, leave an ice cube on the counter, and observe it every once in a while. Notice that it doesn't crack. This is because the more uniform - and slower - rate of heating (air is much less conductive than water) reduces the rate of difference in expansion in the ice cube, so that the energy locked up in the cube is expended without fracturing the cube itself.
Again, the rotor acts in much the same way. If you gradually and gently heat the rotor up when you first use it, you will allow the different parts of the rotor to realign themselves without altering the shape of the rotor.
This isn't sales hocus pocus, it's basic metallurgy, and if you're so paranoid that you think people are saying this just to avoid giving you your money back, then you need to just put your foil hat back on and go on your merry way.
This just confirms my belief that a cheap rotor is garbage. I put a hurting on NAPA's top of the line gen 3 rotors for 50,000 miles and they werent warped/wobbly at all. The rotors on my 96 are the cheapo rotors and they make me think a wheel is falling off every time I slow down.
And you... allowing one man's experience to shape your opinion of something is just dumb. Especially when the man's methods are questionable at best. You should know better.
Iron is iron; it's the same as it was a few thousand years ago. There is very little metallurgy involved, as there are no alloys. It's just regular ol' pig iron. $30 rotors are just as good as $300 rotors. Is the QC as good? No; you might get 1 out of 10 rotors that cracks or whatever. But I'll tell you what; I'll get ten $30 rotors, and you get one $300 rotor, and we'll see who has good brakes for longer, since I have 9 good rotors.