Dabura easily deals with #17 and #18 (assuming Yakon wouldn't be enough), after which things go one of two ways. Either Gohan and Trunks are killed as well, or Shin and Kibito show up with Gohan sacrificing himself to allow Trunks and Bulma to escape. If Trunks escapes, he'd have more incentive to train hard and knowing they were facing Dabura would allow Shin not to be hasty in stopping Babidi. Humanity would be helpless during however long Trunks needs to train in order to stop Dabura. Trunks would kill Dabura at some point after training with the Z-Sword and Bulma would build the time machine over the next 3 years to warn Goku of everything to come. With his power, he would easily destroy #17, #18 and #16 in the other timeline as well as Cell if he were to show up, then helping train everyone in preparation for facing Dabura in 7 years.
That said, the "present" timeline here is far different from the one in the Boo Arc. Gohan wouldn't slack off, Goku would still be alive and Vegeta, although slightly more humanised after spending time training with Future Trunks, would still be closer to his Cell Arc personality than his Boo Arc one. Trunks would show up to aid in the fight with Dabura and Dabura would be killed and without the Otherworld training to create the gap between them, Vegeta would have no need for Babidi and the wizard would be swiftly killed. With that, the events of Super go basically the same until the Zamasu events as they wouldn't occur in Trunks' timeline and would instead be dealt with by the Daishinkan or Zen-Oh. For the manga continuity, this means Goku and Vegeta may not have the incentive to perfect SSB prior to the ToP, which may mean Jiren wins.
As for Trunks' timeline, Cell would've been destroyed as soon as Trunks returned during the 7 year gap after training the Saiyans in the other timeline, so his future would be at peace until his Zen-Oh decides to erase that universe.