Search for debris - delay makes sense
Sailing through the search region several years ago showed a lot of fishing activity, but in addition to this there was significant floating debris, floating islands of rubbish and discarded junk. Whilst it may seem strange to some that a definite debris field hasn't been found, in the context of the area, it makes sense that they are being careful to verify any possible sightings. Plus, bearing in mind that much of the fishing in the area is small operators, with varied nationalities, operating to their own rules (rather than large companies), it really could be some time before feedback comes from these sources. Hoping that further news comes soon for the loved ones of those on board.