So about a year ago, Games Workshop dropped the literal and figurative bomb on the Warhammer Fantasy community. They actually did what they said they were going to do: they ended the Old World. In the storyline, Chaos was ultimately victorious and destroyed the forces of Order. Only a few "good" races survived, such as the Slann and some of the Elves. The god Sigmar survived as well, on a planetoid of Sigmarite that formed the Old World's core, speeding out into space. This massive change in storyline was certainly jarring for long-time devotees of the Warhammer world.
What came next was a complete re-haul of the game itself. From a 200-plus page tome, the rules were reduced to (free) 4 pages: AoS rules
From ranked mass units, loose skirmish formations arose. The bases changed from square to round (unofficially as you can play with any base). The army lists and to-hit and wound charts were replaced by "warscrolls" which gave you all the stats for each unit. Example: Skaven Warscroll
No longer would you compare stats and look up results on a a chart. Every warscroll gave you the to hit and wound numbers. Saving throws remained and so did saving throw modifiers, called the "rend" stat. GW provided new (free) warscrolls for (almost?) all legacy models. Their presentation was rather tone-deaf, in that there were a number of "silly" rules that left smarting fans feeling insulted. Example: Dwarf players with beards got re-rolls, etc. (These appear to be removed from the currently available free scrolls.)
The 4-page rules set had only one scenario at release: battle to the death. This was an error. And to make matters more jarring, there were NO POINT VALUES. The rules stated that players took turns placing models until both stopped. And if one player had 1/3 more or greater number of troops than the opponent, they got a "sudden death?" win condition of their choice. This seemed outrageous to most. No other scenarios or game modes were provided at the time of release. Initial reviews of the new game were overwhelmingly negative. Most described it as a dice-fest scrum in the middle of the board. Many real and imagined possible abuses of the no-points system were discussed. Reaction as a whole seemed very bad. Many players (including me) renounced Warhammer Age of Sigmar for other systems such as Kings of War. The US tournament scene voted overwhelmingly to replace Warhammer/AoS with Kings of War. Kings of War becomes US tourney choice
Finally, GW added a new army, the Stormcast Eternals. This new army comprised the forces of Sigmar. In the story, Sigmar had retreated to his realm, Azyr, and pondered the creation of a weapon to oppose Chaos. His answer was rather Nordic: re-forge the souls of fallen heroes of the mortal realms into nigh-immortal (albeit killable) armored warriors. The result was a powerful and intimidating army of good (hitherto rather absent from Warhammer, to be fair) but which bore a strong similarity to Space Marines.
The reaction to the Stormcasts was rather mixed. Some appreciated the new aesthetic and the presence of a "strong" army of good, others saw them as a cheap imitation of Space Marines and a ploy to boost sales by falling back on GW's biggest selling models.