There was a Jonathon Archer reference a few episodes later, and I am not mistaken one of the first two episodes had a very vague reference to the the original Earth/Klingon contact. fair enough. Sarek was a torch passing from TOS though, which this show is more closely tied to. I have felt for awhile that Context is for Kings is the real opening episode in many ways, and that episode is full of Easter eggs connecting Discovery to everywhere else (Lorca's mushroom slideshow.. (sidethought.. why don't they use that remote viewing function ever again? it seemed useful), Cadet Decker's callout as well. The all blue uniforms to me also seemed a bit like a throwback to both the ENT uniforms and the Kelvin uniforms. Even the Gorn skeleton could be a throwback to ENT, since the first knowledge starfleet had of them was through an Orion speaking to Archer.