Because Wikipedia covers previously published information, it asks editors to avoid speculation as much as possible. The primary policy about this is (cutely) known as "Wikipedia is not a crystal ball".
That said, it is still possible to write some about things that have not yet happened, such as upcoming sporting events, films, and corporate mergers.
Super Bowl 50, for example, already has a detailed entry, because much has already been published on the topic. Even Super Bowl LIV has a short entry because just enough has been written about it. Super Bowl LV, however, is a bit too far off.
The limits are this: there must be a reasonable expectation that such events will come to pass, and there must be published discussion about them, like the next five prolate spheroid trophy contests.
As always, Wikipedia focuses on things that have already happened. Even if those things are about future things.