The Feywild in 5e has only minor differences from the 4e lore.
The planar cosmology described in D&D 5th edition's Dungeon Master's Guide goes to great lengths to retain some consistency with earlier editions of Dungeons & Dragons. For example, the Feywild (introduced in 4e) still exists, as does 4e's Elemental Chaos, but now the Elemental Chaos is a ring around the separate elemental planes which existed in 3e and earlier.
In other words, D&D 5e intentionally attempts to retain lore compatibility with earlier editions, and this is particularly true for the Feywild, which was an original creation of 4e that was maintained by 5e, and did not need to be changed to accomodate any lore from earlier editions.
The "core" Feywild lore for 5e is described on DMG p.49-50. It is described as a realm of everlasting twilight where the sun never truly sets or rises, inhabited by magical creatures, with civilized lands ruled by the thee seelie fey Queen Titania of the Summer Court and the Queen of Air and Darkness of the unseelie Gloaming Court, existing parallel to the Material Plane, where natural features are exagerrated, which can be entered or left by a fey crossing, and which optionally may cause memory loss or where time may pass at a different rate. This is the limit of 5e's lore on the Feywild.
The 4e books Manual of the Planes and Heroes of the Feywild are largely compatible with this lore, with only minor differences. The Summer Queen is named Tiandra, rather than Titania, and the Gloaming Court is not so explicitly aligned with the unseelie fey. The 4e lore describes a greater variety of terrain, such as lands of permanent winter, and more than two factions among the fey. However, it is otherwise largely the same, and the 4e books greatly expand on the brief description given in the 5e lore.
Aside from this, the multiverse cosmology of D&D 5th edition holds that every DM's game is its own parallel world, and therefore ideas of "canon" only really matter as far as your own campaign world. As per DMG p. 4:
The world where you set your campaign is one of countless worlds that make up the D&D multiverse, a vast array of planes and worlds where adventures happen. Even if you're using an established world such as the Forgotten Realms, your campaign takes place in a sort of mirror universe of the official setting where Forgotten Realms novels, game products, and digital games are assumed to take place. The world is yours to change as you see fit and yours to modify as you explore the consequences of the players' actions.