I'm not building a roster for the next two years, I'm building it for the next 10. Especially in an environment where the cap is going to be rising aggressively, you should lock down your stars (or future stars) if they'll let you.
This moment in time (expiring ELC) is when the team and players interests most align. Player is trying to hedge away downside risk for career ending injury, and the team is trying to lock a guy in at a below market salary for as long as possible. If you bridge, the player will already have high 7 figures or more in career earnings, and be closer to UFA in a rising cap environment.
There's risk from a team perspective, so you shouldn’t treat every guy like this, but Luke is as close to a lock for future star as anybody in this league right now. Gotta strike while the iron is hot, and work out the #4-6D contracts around that.