As far as I know, ISA is still used for some legacy hardware, e.g. PS/2 keyboard, PC speaker, floppy controller, but it's almost purely conceptual by now. The ISA bus might not even exist outside a single chip (e.g. SuperIO controller.) I don't know about MCA, but I think that was only on some 386 and 486 IBMs, so that would certainly be irrelevant to have in by now.