You will still have the legendaries that you got from legion and when you start Battle for Azeroth (BFA), the legendaries will be weaker and weaker for each level up.
The level cap in BFA is 120 and when you are around 118, then your legendaries are more or less totally worthless.
BUT the secondary stats are still good, so keep the legendaries until you get better secondary stats.
Other posts
- +63 Key for 740 ilvl Reward in Legion Remix Mythic+
- The Ultimate Legion Remix Gearing Guide: How to Max Out Your Item Level Fast
- What comes out in Midnight - World of Warcraft
- Legion Remix: Everything You Need to Know About WoW’s Fast, Fun, and Fel-Filled Seasonal Event
- Week 1 Coffer Keys Guide for Patch 11.2
- War Within Season 3 Pinnacle Cache Guide: Massive Reputation Gains in Patch 11.2
- Gear update week 1: Get 2 Veteran pieces 668+ ilvl
- All lore objectives in 11.2 Karesh
- Timers (spawn time) on Objectives (Invasions)
- All side quests in 11.2
