The "universality" exists only for now because wasm is at the toy-language level. The more it will evolve towards being helpful for production, the more opinionated and complex it'll become which will reduce the number of languages supported and platforms it runs one.
Source: every language vm under the sun (CLR, JVM, Neko, etc.)
Source: every language vm under the sun (CLR, JVM, Neko, etc.)