No, WWE are not signing Kenny Omega or The Young Bucks before the end of 2018.
Sorry, but the fact that trio have current contracts with New Japan Pro Wrestling (Omega's is due to run out next January) means there's next-to-no-chance they'll suddenly pop up on Raw or revolutionise NXT by bringing some Bullet Club magic to Full Sail University. It could happen in 2019, but this year is a bit far-fetched.
Not to worry though, because there's a ton of other talent WWE should be looking to bring in before the end of December. Better yet, all of them are available; some already have company experience and deserve another shot, whilst others are stars of the future or making so many waves in mainstream media that WWE would be foolish to ignore them.
Then, there are the workhorses who have never had the chance to show what they can do under Vinnie Mac's banner. Those guys must look at the success fellow ex-TNA peers like AJ Styles and Samoa Joe are enjoying in WWE with a mixture of pride and envy.