This is sad, TBH. I've found global search very useful for searching for example-uses of rarely-used libraries. Having all that at my fingertips was useful.
I understand legacy examples aren't useful for everyone, but for me they often were, and now a lot of code will be completely unfindable. :/
Think of niche programming languages and the like that've passed their heyday - I guess tagging might help, but a lot of people don't bother tagging projects.
Also, I guess this includes one's own projects? I have about a hundred repos of various ages, and it's easy to lose track of them. Not being able to search through my own code sounds like a bit of a bummer (Though I don't have an intuition for how often I search for stuff in my own repos, TBH).
Pity there wasn't a better solution available to solve their problems.