As of May 2020, WWE has instituted the "Brand-to-Brand invitation" rule, which allows wrestlers to appear on another brand "four times a year," implying it will go on longer than a year. However, details are few and far between as to what constitutes a Brand to Brand invitation.
Fightful will keep a running list of instances, and this article will likely evolve as more happen. You can see the active WWE roster at this link.
Baron Corbin (1): WWE Raw match with Drew McIntyre on May 18.
- From The Web