The Details of This Trade Are
Cavs: In: Cameron Johnson Out: Jarrett Allen, Jaylon Tyson
The Cavs switch out two relatively equal value players in Jarrett Allen and Cam Johnson, and reorganize their roster to allow for Mobley to play center, improving their shooting. Jaylon Tyson is given to the nets as a cap filler.
Nets: In: Austin Reaves, Jaylon Tyson, Maxi Kleber, 2 1st round swaps Out: Cameron Johnson, 1 LAL 2nd
The Nets move on from Cameron Johnson and add a young piece in Austin Reaves who can push them further into tank mode for next year while adding upside. Jaylon Tyson and Maxi Kleber are both mostly cap fillers, but they could be played by the Nets to build value for a future trade. The firsts are a gamble, but could be valuable is for whatever reason, Doncic leaves. Even without the firsts this isn't a bad tanking move and if the 1sts turn into something this is a clear win.
Lakers: In: Jarrett Allen, 1 2nd Out: Reaves, Kleber, 2 1st round swaps.
The Lakers need a center, and Jarrett Allen is only 1 year older than Reaves. So they swap out Reaves, who is less valuable with Doncic on their team, for Allen, a solid 1 time allstar center. Reaves is a hard loss, but Allen is a better fit, and the 1st round swaps probably won't become anything.
This trade relies on a few things
The Cavs don't win in all this year and shooting is the big issue
This one is almost certain. None of the Lakers centers prove reliable and the FA market is relatively dry
The Nets don't decide to compete next year using their current cap space