Almost any update, OS, App, FW, config updates etc has an impact on hoa a device work. We all use our devices differently with different apps, different periperals and with different settings, this makes it very hard to generalize and say that an update has amazing batterylife or not.
Apps might need to be updated to accomodate all the "under the hood" updates that iOS 17.6 has, periperals might need to be updated too
In the past we have seen updates to the BMS and who knows (guessing now) that might be the case here too.
Give it a few days, update periperhals, update apps and if you know you are running a few odd apps, configs or solutions that might not be mainstream and encounter crazy battery drain, disable these to see if that might help.