As noted, the rule will see four RAW Superstars appear on SmackDown each week while four SmackDown Superstars appear on RAW each week. The gimmick was created as a response to ratings pressure from NBCUniversal (USA Network) and Fox. Vince did not want to give up the idea of separate brands, but the networks want star power on both shows and there has been a feeling that the brands don't have enough star power individually. Furthermore, it was also reported that Fox wants RAW and SmackDown storylines on the blue brand show when it goes to their network on Friday nights in October. There has been pressure from both networks to have the top WWE Superstars work both shows.
The Wild Card Rule will potentially cause issues for WWE live events, such as false advertising. Due to the way WWE creative operates these days, WWE likely won't plan out these weekly Wild Card Rule appearances in advance, which could lead to incidents where Superstars have been advertised for live events, for weeks or even months, but they're pulled from those live events to appear on TV at the last minute.
While WWE likely won't plan out the Wild Card Rule appearances in advance, it was noted that Roman Reigns is expected to appear on both RAW and SmackDown often. We noted before how NBCU recently asked questions about why WWE gave up a star like Reigns to SmackDown in the 2019 Superstar Shakeup.
We've reported on how WWE has made recent hires to help bring live event business back up, and they noted during the Q1 2019 earnings call that they are focused on bringing that part of the business back to where it should be. The WWE Wild Card Rule could create more of a decline in live event business, at a time where they're focused on getting it back up. There's no word yet on if the Wild Card Rule really will help with the TV ratings, but we should know within the next few weeks. It's believed that the gimmick could bring a small increase in the numbers, but likely not a huge turn around.