In an update on the situation involving Rusev and his upcoming Casket Match against The Undertaker at Greatest Royal Rumble, Bryan Alvarez of The Wrestling Observer Newsletter reported that from what he understood, the reason why WWE officials initially decided to replace Rusev with Chris Jericho before putting Rusev back in the match was simply because they felt that Jericho would be able to have a better performance with Undertaker.
Alvarez said the following:
"There is no scandal involving Rusev, it is all storyline. Rusev is no longer in the match with The Undertaker. He has been replaced by Chris Jericho. They ran some goofy stuff on social media to, I guess, get people talking — which they did. Rusev I believe is going to be in the Greatest Royal Rumble so he’s still on the show.
“The point of this is that Rusev is not quitting. He’s not leaving. He’s not getting fired. Nothing like that. They just decided Jericho vs. Undertaker would be a better match even though they announced Rusev vs Undertaker before they figured that out.”
No word on why they decided to go back to the original plan with Rusev in the match, but as was previously reported, the storyline explanation being given is that Rusev's wife Lana "changed her mind" and decided to allow Rusev to compete in the match after all.