With respect, your comment is not particularly well-informed concerning either PHP or WordPress. WP is not written in PHP in any modern sense of that term. They got suckered into maintaining backwards compatibility with an API written before PHP had support for classes. The codebase is entirely procedural, and cannot be modernized. WP internals are frozen in time in 2001, and WP development does not resemble modern PHP development, which has reasonably good tooling.

So, the good thing is that Google will not push WP to run on an alternate language, because the entire value of the project is its API compatibility. That's also the bad thing.