Technically, yes.
But in reality, not all the time. One reason is because of
propriety formats. Realplayer uses a propriety codec called Real
codec, and the files are encoded. You will have to download
RealPlayer to play their files. Nowadays with a wide range of
players and alternatives, it's not so bad, but that's still one of
the reason you can't change a program type as you wish.
The next reason is different programs are coded differently, the
same files may open in a different way, but of course that's rare.
But just in case, we always recommend the default program so that
it opens in a right way. When nothing works, alternatives come
in.
