That was no "kick" lol...and he deserved to be KO'd for such an attempt...and I'm a big Maia fan. That KO is the precise reason you go train kicks...its like a fireman afraid of heat.
His cardio when grappling is actually solid, his cardio gets weak as he strikes, why? Because he has horrid striking technique...he's a heavy arm puncher, he loads everything up, its draining.
Maia's made some improvements over the years, and failed in other areas. To me, Maia is "what could have been". Young BJJ types should learn from mistakes, and steal his productive work.