Blizzard are offering a free weekend of World of Warcraft for those who have played the game before but quit for any number of reasons. Those who jump in will also have trial access to Battle for Azeroth expansion if they didn't buy it.
World of Warcraft free-to-play-no-subscription promotion will run from 21 through 24 March 2019 and will let players go through full content either the last expansion they initially purchased or World of Warcraft: Legion, whichever is greater. Those who didn't purchase Battle for Azeroth will not be left empty handed, not entirely at least.
Such former players will have access to the trial content of Battle for Azeroth, meaning they can play for three hours or up to A Nation Divided quest for the Alliance or We Need Each Other in Horde's case. After that, their experience with the bonkers version of Sylvanas will cease.
In order to access World of Warcraft once again, players will just need to download the Blizzard Battle.net launcher and then the game itself. Any updates will be automatically downloaded and the Play button will be highlighted the moment the minimal viable amount of content was downloaded. Players can already go into the game at that point but the background update might cause latency and the missing assets could impair the experience.
It is former players who stopped buying expansions before Legion that will benefit the most as Blizzard's new policy will see all expansions added to their account, except for Battle for Azeroth. The policy change didn't happen that far in the past itself, so when paired with the free weekend, one could start suspecting WoW is shedding players at an alarming rate.
The fans' displeasure with World of Warcraft: Battle for Azeroth is no secret and even those who purchased the expansion often leave the game due to their disillusionment. It remains to be seen whether these will manage to revitalise the player base.