I have never seen that, so I don't really care what it would say.
I think it more likely that they just use "lower" grade stainless steel, which is inherently magnetic. THe "higher" grade ones are not really necessary for something which is only used in a regular environment for a few hours a week.
They don't need the super-high anti-corrosion properties of something that woukld be exposed to the elements 24/7.
I think you are maligning Ikea products without any actual evidence.
There is no such thing as your thought: metal grades are not a scale worst to best.
Every single grade has a specific purpose that is its existence reason.
That specific purpose is a trade off, a plus comes with min.
The same reason that drugs have "side" effects.
Your first "I think" that "lower" grade (that is, the mathematical) number implies magnetism, is just wrong "thought".
The cheapest 304 grade (kitchen, in construction named A2) is very slight magnetic, the second-cheapest 316 grade (construction A4) is not magnetic at al, and all "higher" numbered grades are, in quite different degrees, magnetic, upto clinging on alike on non-stainless steel.
The "lowest" numbered grades have the best corrosion resistence of all grades.
That "best", comes with the min of mechanical properties reducted to half of non stainless steel. They're also "soft", that is, easier to wear, that is, losing material, and if it's a thin layer like I've seen (said it before, still you come up with your second "I think") on some IKEA products, it looks like your socks after a while not cutting your nails.
Then, as also said in previous post, it's reveiled what is under it: plastic, wood, or... non stainless steel, the latter causing a magnet to cling, even "through" the stainless coating.
As I illustrated with the analogy of a hammer head wrapped in paper - it looks like the magnet clings on the paper, but it of course clings on the steel of the hammer head under it. Just like the paper, the stainless steel is just like the paper a thin layer material that doesn't influence magnetic fields.