Yeah, there are those too. My laptop shares a socket and TDP with some Ivy Bridge i3's, but the chipset has artificially blocked using "Core" processors, so if I were to install one, the laptop would shut off exactly 30 minutes after booting. In other cases, the microcode for the CPU you're trying to put in might not be there, and it either might not boot (CPU unrecognized) or might boot but would not work correctly (e.g. show as "unknown CPU, missing AVX extensions).
Upgrading laptops is really hit or miss.