Kidd will be important in Elbaph when the 2nd wave of God's Knights come after Zoro and Sanji beat Sommers and Killingham.
Once the main Straw Hats go down, we'll see outside reinforcements spawn in for three reasons:
1. Elbaph was important to Rocks, so it will be important to Teach
2. Since Morgans reported the Straw Hats fled with the Giant Pirates, everyone knows the Straw Hats went to Elbaph. This is important because: A, the Straw Hats Allies will want to visit them (think Boa saying she wanted to see Luffy when she needed to flee Amazon Lili), and B: Blackbeard and Mihawk know Luffy is a serial recruiter, and neither Blackbeard nor Cross Guild can afford to have Loki join the Straw Hat Pirates.
3. Imu's giant Haki dump upon entering the country is going to trigger everyone in the New World with top tier Observation Haki. Shanks, Mihawk, Zunesha, etc. Possibly Pluton, but that's another story. While Luffy getting Loki is problematic for other New World Yonkou Crew, Imu getting Elbaph SUCKS FOR EVERYBODY, I can see a temporary alliance forming between factions to kick Imu off of Elbaph, like on God Valley with Rocks/Roger/Garp forming a small alliance before Rocks got Domi'd.
Kidd and his Crew will show up in Viking Giant Mechs once the Straw Hats get gimped up and Imu summons more God's Knights, probably Shamrock, also maybe a Gorosei in Garling.