Why UE sends UL information transfer emm status message and how network handles this?

Hi Experts,
When Network sends LTE RRC connection release UE sends ul information transfer emm status message.
Why UE sends this and how network handles this?

I think UL information transfer or DL information transfer used in RRC connected mode .
Purpose is to transfer NAS or non 3gpp dedicated information.
After RRC connection release, UE move to RRC idle.

We are using simulator for network.
The below is the call flow:
Lteattach -> pdn est -> rrc conn release by network -> serv request -> auth/sec procedure -> drb reest -> serv accept -> rrc conn release.

It was for this 2nd release ulinfotransfer emm status from UE observed.
I removed DRB reest part.
Now UE sending serv request again.