If it worked so well before, why mess with it again?
After the unexpected success of this year's Oscars sans host, the indication seems to be that it'll be the norm going forward.
Confirming the news to Variety, ABC - which is responsible for the telecast each year - said that they will "will not mess with that format to the best of our ability." Compared to other awards ceremonies that season, ratings for the Oscars actually went up on previous years.
However, it's quite possible that the uptick for this may have been due to the controversy surrounding Kevin Hart, who was initially signed on to host. Hart withdrew himself from the ceremony after historic tweets of a homophobic nature resurfaced. While some in Hollywood - notably, Ellen DeGeneres - urged him to continue on in spite of the controversy, the ceremony ended up without a host.
Given how well the ceremony went, despite the likes of 'Green Book' winning, it seems like the right idea to continue on without a host - even if we'll never get moments like this again.