Dubois is aiming to become a two-time world champion when he faces fellow Briton Wardley at Manchester’s Co-op Live Arena on Saturday.
He joked that they would “have a bigger party this time” before insisting the previous gathering had no influence on his performance against Ukraine’s Usyk.
“It wasn’t why I lost,” Dubois said.
“I went up against one of the greatest fighters of this generation and I’m glad I have the experience of sharing the ring with him twice.”
Dubois and Charles parted ways after that loss at Wembley, ending their 18-month relationship, but they reunited later in 2025 and have been working towards returning to the top of the sport.
“He was ticking over and training,” Charles said.
“He went on holiday for five weeks to get a bit of sun and went to Tony [Sims] before coming back to familiar territory.
“There was not a lot of talking, there was a lot of embracing. I love all my fighters and when he walked in with his father we embraced each other and I said ‘welcome home’.”