If there is any right time, it is now. At 43 years old, The Artist is nearing the end of his run as a serious title contender. Before his run is over, he should win a world championship in WWE. He should have won the WWE Championship in 2018, but since that did not happen, now is the time.
I would book Rhea Ripley vs. Nia Jax. Fans are hot for this story in a way they may not be in another month. WWE has wasted too much time not booking Mami in serious title matches. She can test Jax in the ring, even if the title match is likely to end in a disqualification to protect both.