I don't know about other brands, but for ThinkPads (both in the IBM and Lenovo eras), there was often a stated maximum RAM that was based only on the capacity of SODIMMs available at the time of manufacture.
But it wasn't an artificial limitation. In practice, once larger capacity memory became available with the same technology and form factor, it would work fine. I have upgraded several ThinkPads with memory beyond what the original datasheets said was possible.
But it wasn't an artificial limitation. In practice, once larger capacity memory became available with the same technology and form factor, it would work fine. I have upgraded several ThinkPads with memory beyond what the original datasheets said was possible.