Tank was written out of sequel because Marcus Chong turned nasty
Apparently after the huge success of the Matrix, he wanted a bigger check for his part. I agree, if you are part of a movie that is huge, you should probably earn more on the next movie, even if it is a nod of respect or gratitude for doing a good job on the 1st. I thought he did a great job on the 1st.
But he got demanding and then did something he shouldn't have, he apparently threatened producers.
I believe police got involved. He eventually tried to sue!
Not only did he burn his chances of being in the sequels, he burnt his name in Hollywood and never did anything of note ever since.