
Samsung Galaxy Note Edge
The latest firmware for Samsung Galaxy Note Edge (SM-N915W8) is N915W8VLS1CPK1 with Android 6.0.1 (Lollipop), released on November 28, 2016 for 6 regions (CSC). Every official firmware build for SM-N915W8, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/N915W8VLS1CPK1
SM-N915W8 started on Android 5 and has received 1 major Android upgrade; it now runs Android 6.0.1 (Lollipop). The newest build, N915W8VLS1CPK1, was released on November 28, 2016. No new build has appeared for 120 months, so regular updates for this model have most likely ended.
Specifications of SM-N915F, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

SM-N915V

SM-N910V

SM-N916S

SM-N920AZW

SM-N900V
The newest firmware for SM-N915W8 runs Android 6.0.1 (Lollipop): build N915W8VLS1CPK1, released on November 28, 2016.
The latest build for SM-N915W8, N915W8VLS1CPK1, was released on November 28, 2016 (9 years ago).
SM-N915W8 has had no new firmware for 120 months, so regular updates have most likely ended.
Yes, all firmware files for SM-N915W8 are 100% official, original, and obtained directly from Samsung servers.
To flash SM-N915W8, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-N915W8.