Yes, that is exactly the part that concerns me. This doesn't need more code, it needs desperately less.
I’m with you, but if you’re maintaining a massively popular open source library, where backwards compatibility is expected, you’re not going to remove features without careful consideration. For an important bug fix, it probably does make more sense to just fix it without breaking anything first, then talk about a more careful deprecation/removal plan.
"Filtering code"? This sounds like trying to plug hole in dam with one's finger. And the the hole is several meters wide.