Not exactly. Simon has been made swifter, and certain items have been overhauled, such as the holy water becoming the glass bomb, which you use to clear certain rocks and roadblocks. Subweapons work like Symphony of the Night, and I plan to add many new ones.
There are now 3 classes of weaponry: Whips, Daggers, and Greatswords.
Whips deal medium damage and have a medium delay when used. Daggers deal minimal damage but can be used quickly and consecutively. Greatswords have a long delay but deal great amounts of damage.
You have 4 stats: Attack, Defense, Luck, and Levels. Attack and defense depend on your weapon and armor, and luck depends on accessories. Levels are simplified, and you should be able to play the game pretty well without grinding. Shops sell more general items with the occasional weapon. Relics like the white crystal and such are found elsewhere. There are bosses inside and outside of the mansions. Castlevania is going to be much longer and have multiple areas.
Day and night works mostly the same, enemies' defense and attack double at nighttime. Hearts are no longer currency, only attack ammo. Spells and critical arts work like SotN, where you input button combinations. Simon has 2 hands to equip items with. Greatswords are 2-handed, while other weapons can be paired with a shield or something else. Simon has a use item button for one time use items, such as food, laurels, or garlic.
Towns have been overhauled. They are much shorter and townsfolk either tell you useful information or offer some sort of side quest. Towns will have warp points in them, as well as saverooms in the churches. Saverooms will also appear outside of towns, so you don't have to travel back to a town to do so. Citizens still go inside at night monsters replace them, however, you can still enter buildings at night.
That's just a few changes off of the top of my head.