during my flight SIN-DOH-LCA a few months back, it was the same as well. was pleasantly surprised, since our first leg was delayed, and i was worried we wouldnt have time to check out the lounge.

basically they had set up a desk, and were randomly asking transiting passengers to do a bag check. most of us were able to just walk directly into the departures area.

initially i had thought they did it as our flight was delayed. but seems like its not the reason since OP's flight was on time.