Yes, that is true. You need some pro skills to complete an upgrade and swapping out all memory chips to 6 or 8gb. I can do it. I work as dr-engineer for 20 years and do this stuff almost everyday (micro soldering) but i do not have the machine
It would be interesting knowing the specs of memory chips -brand and chip number.

Probably this machine is an old used they are selling?! But there is no real evidence for that yet, or? We will see.