It is a good sign
LUD changes usually is a good sign. The worst case is nothing happened. Based on my recent EAD and AP renew with TSC, I have the following experience.
For EAD, LUD changes for two days without messgae changes, then the message changes " card is ordered ....", then another two days later, message changes to " This case has been approved on ,,,,,".
For AP, the same thing happened. First LUD changed for two or three days, then the message updated to "This case has been approved...." in about 3-4 days.
So these LUDs mean at least they touched our files. The final results will depend on the cases themselves.
Let us hope and pray before EB2 runs out too. We also pray for EB3 friends to get earliest possible approvements...