Bomberman shrank the arena when the matches went to sudden death. Pretty sure others also did this (certainly common in single player games of that era and earlier - arguably Joust with it's rising lava is close to being the first for that sort of thing)
While Battlegrounds was not the first battle royale game, its release to early access in March 2017 drew a great deal of attention, selling over twenty million units by the end of the year,[18][19] and is considered the defining game of the genre.
That's what the grandparent was saying: Brandon Greene, the man mostly responsible for PUBG was also responsible for H1Z1 (SOE licensed the Battle Royale mode from him for H1Z1 and hired him as a consultant):
https://www.pcgamer.com/battle-royale-modder-brendan-greene-...