Why is quran package installed by default on Texlive2020

[Karl Berry]

    Subject: Why is quran package installed by default on Texlive2020

Because every system-independent package included in TL is installed by
default (because the default is scheme-full), regardless of what
collection it's in, or anything else.

    why is the package quran included in collection-xetex?

That's a separate question, and the answer is: because when it was first
released, it only worked with XeTeX. As far as I can recall, anyway. As
Arthur says, I may have just taken the CTAN location as evidence.
Anyway, working (only) with xetex is the reason that I put any pkg in
c-xetex.

Now that I know quran works with LuaTeX also, I will move it to
c-langarabic soon, unless a better choice presents itself. --karl