Irrespective of whether Julia ends up the winner of the shift or if the shift happens, it is quite possible for trends to reverse very fast. See Perl or Objective-C for that matter.

https://www.tiobe.com/tiobe-index/perl/

https://www.tiobe.com/tiobe-index/objective-C/

In 2006 (for Perl) and 2014 (for Objective-C) it was clear they had the momentum for their particular space however their limitations were well known and as soon as a better language came along the momentum flipped in an equally dramatic manner. Python is much more widespread so it will remain strong in some areas but you could see the flip in ML/DS given challenges productionizing across broad capabilities (not just doing NN's).

As the joke goes -- python is the second best language for everything, if you know only two languages. With ML expanding beyond narrow big tech domains there will be need for specialized languages like Julia (and others perhaps like Mojo etc..)