Luckily, ahead of its May 8 Season 4 finale, MacGyver was renewed for a fifth season, making it possible to usher in new episodes of perfectly timed chaos in 2021, more than likely. Even better, viewers are getting a proper(ish) send-off for Season 4 with a finale that should sit well with most fans, as opposed to an abruptly ended season. As fans of a plethora of other shows have seen, dealing with mid-season endings has been par for the course.
In this case, however, things were already set up for a May finale, in a way. Season 4 of MacGyver was initially given a 13-episode order. It was later given an additional nine episodes, but before that happened, Episode 13, which airs on May 8, was written to be a sort of mid-season finale, with the rest of the episodes picking up later on. Since this now serves as the Season 4 finale, those other episodes will air as part of Season 5.
Source : https://www.distractify.com/p/macgyver-season-5-renewal