Both yes and no, I guess.
As you've noticed, LLD consists of 3 (or 4) different separate linker implementations, for COFF, ELF, Wasm (and MachO). Each of them try to work as a drop-in replacement for the native linker on each platform.
In the COFF case, LLD, in the shape of lld-link, acts as a drop-in replacement for link.exe from MSVC. (Whether link.exe or ld.bfd is the true right linker to emulate as the native one can of course be discussed, but that decision is way before my time here.)
Since the 6.0 release, we've added another layer into the mix; if invoking ld.lld, which would normally be handled by the ELF linker, we check the -m parameter, and if it indicates that it should link for a COFF target (i386pe, i386pep, thumb2pe or arm64pe), it instead translates options from ld.lld style into lld-link style and invokes the COFF linker.
As the internal linker mechanisms within the COFF linker mimics link.exe and not ld.bfd, this emulation isn't perfect, but it does work in most cases now. This was first present in the 6.0 release, and since around September in the latest SVN trunk/upcoming 8.0 version, ld.lld should work in many cases as a replacement for ld.bfd.
It doesn't implement every single feature of ld.bfd, and it doesn't replicate ld.bfd's behaviour exactly (I just recently noticed one limitation, regarding linking crtend.o from libgcc, for i686 with dwarf exceptions), but for many cases it does work.
We haven't tried to implement every single option out there (not yet at least), but the most commonly used ones do work. (It's possible to compile all of VLC for Windows with it, which involves building over 100 various dependency libraries - although they are mostly built as static libraries so not all of them stress lld.)
Linker script isn't hooked up yet though. The only places I've ran into it being used for windows, is for passing lists of object files, which can be done just as well via response files. Therefore I've worked around that issue by adjusting build systems in a few places to use response files instead.