Wikilinks not made for names that begin with @ – could this be changed?

I realized this morning that I’m unclear about some things:

  1. Does the upcoming change mean that single brackets will no longer prevent automatic wikilinking (thereby also resolving @lyndondrake’s request), or will only double square brackets work?
  2. Will this also work if there is additional text inside the brackets, such as [see @Foo2021something, p. 23] and [@Foo2021something; @Bar2021other]? Or will it only be for the limited case of (e.g.) [@Foo2021something]?
  3. Is any of this affected by whether the document alias has @ in it? I.e., is the expectation that the alias is Foo2021something, or must it be @Foo2021something?