Well obviously anything is possible. What we know is Warner played poker - a lot!

Warner built a poker room in is mansion in 1937, when, I believe the chips were ordered

Here is a line from Neal Gabor’s 1989 book on old Hollywood

Here is a letter to Hunter Stromberg of MGM reminding him of an unpaid poker debt.

It has been said that Warner loaned an under contract Betty Davis to MGM to settle a poker debt.

Again, anything’s possible.