Things look normal. rc3 is neither particularly small or particularly large - it's pretty much average for an rc3 release for the last couple of years. As usual, things have picked up a bit from rc2 as people are finding things, but that's normal and not worrisome.
Nothing particularly stands out in the shortlog (appended) or the diffs either - the changes are pretty spread out, with all the usual suspects: drivers (gpu, sound, i2c, networking etc), architecture fixes (x86, powerpc, arm64, risc-v, s390), and various tooling and documentation updates. And to round it out, a random smattering elsewhere (core networking, kernel, some mm and filesystem noise).