I don’t know if someone’s pointed this out already but I just realised something….
So, as we know, Keith is the right arm of Voltron, and Shiro forms the head.
Shiro’s right arm is Galra tech. Not his full arm though: it seems like the part where the Galra arm ends and real arm begins is just about halfway, slightly above his elbow.
This means Shiro’s right arm is half-Galra.
SHIRO’S RIGHT ARM IS HALF-GALRA.
The foreshadowing was there the whole time. Dreamworks played us like a damn fiddle.