PMS 1.21.4.4054
Plex combined them into the 2016 version for me. A Split Apart and Fix Match quickly resolved things. Using Plex Web, click on the three vertical dots in the lower right corner of the Show icon/cover art (not at the season or episode levels). Split Apart and Fix Match available in the resulting menu.
Edit: If I Plex Dance the shows, and return the 1984 version first, Plex recognizes the shows correctly (I did not try returning the 2016 version first).
/TV Library
../MacGyver
..../Season 01
....../MacGyver - s01e01.mkv
../MacGyver (2016)
..../Season 01
....../MacGyver (2016) - s01e01.mkv