The new edition of Warhammer 40,000 states that mankind has entered the Time of Ending, with the long-awaited fall of the Imperium imminent. Fans weren't fooled, since the in-universe calendar was actually rewound by about 4 decades in order to make the "Time of Ending" take place before year 41000. As always, The End of the World as We Know It is still very, very unlikely.
On the other hand, the series has seen the introduction of new races, and changes to old ones — the Tyranids, for example, are a vastly different force from the Genestealer infiltrators that first attacked the Imperium.
The rules of both systems managed to avert this to some extent. 8th edition fantasy shook up the way the rules had worked for years in a huge way and 5th edition 40k altered things to a big extent too.
Quite recently averted with the brand new 7th Edition codexes, and the Gathering Storm plotline which inflicts lasting consequences for multiple factions. Abaddon has finally conquered and destroyed Cadia, leaving the Cadian regiments as The Remnant, the Eldar have managed to partially summon Ynnead and a new movement is opening up the possibility of the reunification of the Craftworld and Dark Eldar, and Primarch Roboute Guilliman has returned.
White Wolf is not fond of this trope. In the Old World of Darkness, any apocalypse foretold in a gameline would come to pass when that game went out of print, ending with the Time of Fire when the oWoD ended. The New World of Darkness is designed as a more static universe.
Interestingly enough, in New World of Darkness, the God Machine spends it's existence maintaining the status quo.
Scion has the Overworld War take noticeable steps between the three main books.
Exalted is even more blunt about shooting this trope in the face. In the second book they ever published, they made it abundantly clear that the metaplot would not be moving forward canonically from the Day 0 of Realm Year 768, as the characters are intended to deform and reshape the setting around them in their image. More detail has been given about the setting as it stands—mostly to provide new and interesting ways for Creation to go to Hell in one way or another, or for players to fight against it—but nothing has definitively gone forward and progressed information on the inside of the core book. Actually, in Exalted, Status Quo may well be God. On the other hand, starting characters can start off with a power suite to murder the gods.
3e does project what could happen in the years following Day 0, showing how Creation changes over time, but again the characters are fully expected to crash in and shake things up.
Ravenloft's mysterious Dark Powers explicitly apply Laser-Guided Amnesia and Phlebotinum-Induced Stupidity to the populations and even darklords of the various domains in order to preserve the general theme of each domain. Hence, for example, Vlad Drakov will never incorporate firearms into his Medieval-style army, even though surrounding domains have them, firmly believing that magic and guns are "coward's weapons." Likewise, many supposedly-human darklords are centuries old, and the residents of their domains don't seem to notice.
In the CD&D Hollow World setting, the quasi-divine Immortals slapped an extremely powerful spell on the place to ensure that cultures preserved within it wouldn't change.
BattleTech seems to avert this with the different eras (Star League, Clan Invasion, Jihad, etc...), but plays one constant straight: Don't expect anything that threatens to seriously shift the overall deadlock to last for very long. In fact, it's usually the point where everybody goes back to shooting each other that begins and/or ends each Era.
Likewise, other factions may come and go, but the five Great Houses that were introduced first (Davion, Kurita, Liao, Marik and Steiner) are clearly here to stay and remain in charge of their respective Successor States roughly until the heat death of the universe. The Free Worlds League may currently (as of this writing) look like it's falling apart, but it's really just a matter of time before it pulls itself back together with once again some scion or other of the extended Marik family at the helm.