It is a bad idea to have fan events for a three-hour movie at one in the morning. In any case, the audience won't be mentally prepared to see a three-hour movie. Devara is a mass-market movie, thus there are already huge expectations for it. Holding those early events, which are mostly attended by fans, would be extremely risky.
There's a great chance that bad press will start circulating from these events even before the release. If not, there is only one possible explanation: koratala must have produced a flawless product with zero latency. With their long runtime, the early shows can only be explained in this way.