If it's a shared template here on Community Central then yes, you can edit it.

How do I know if it's a shared template?

I mean, if it's a template here on Community Central being used on different wikis - that's the idea of "a shared template".

If you aren't sure, give a link to the template you're asking about.

In that case, it's shared. I've seen it on the Monster Hunter wiki.

That's probably something the staff forgot to remove, because I don't think anyone replied to other people's requests recently. If their wikis are there, they probably added them themselves.

Why are you talking about staff? The template has been created and edited by the community. You actually just did!