As noted on the Wrestling Observer website, since Saturday, Bayley was a 36-to-1 favorite to retain her title but Alexa Bliss is now the 45-to-1 favorite to win the match. That doesn’t necessarily have to mean that she will win the title because she could win via DQ or count out but the odds would seem to indicate that a title change is likely. The big odds swing would indicate that there was a change of plans since Saturday.
Big odds swings happen once changes are known internally so that’s why we ignore the betting odds until the weekend of the show. Vince McMahon has been known to book wrestlers to lose in their hometown (Bayley is from San Jose, the site of tonight’s PPV).