One might imagine that CHERI and Wasm are similar technologies, since they both talk a lot about security and capabilities and so on.
However, CHERI works by making Unix processes safer, while Wasm works by not having Unix processes at all. It's "take the C virtual machine and make pointers smarter", vs. "make a new virtual machine". There is some overlap in the problems they can solve, but very roughly speaking, they work in opposite ways.