If Korea wins Berlin, VS will probably be able to put in Lakia since Korea will have an extra slot for champions due to the winner of Berlin auto qualifying.

It's because of the way the point system works. You gain circuit points for where you place in tourneys. If you change the team around, you must have three of the original members either in the starting lineup or as substitutes. Essentially, they have no room for Lakia since they brought in the best duelist Korea and a smoke replacement for glow.