I would-- but as an 'extra' issue or miniseries that wouldn't interfere with ongoing storylines.
In fact, what I'd want to see would encompass both teams' histories.
A meeting between the ADVENTURE or COCKRUM/GRELL era Legion with the Fab Five + Lilith and Mal would be MANDATORY!
Then, the Levitz Legion could encounter the WOLFMAN/PEREZ seven.
The 'adult' Legion of the 5YL years could team-up with the 'evil lesbian Raven' team...
...the reboot kids would hang out with YOUNG JUSTICE...
and, finally, the rebel Legion of current issues would tussle with whatever the Titans membership will be post-IDENTITY CRISIS.
Sounds like one way to re-intro the TIME TRAPPER, to me.