Essentially the gap between exposure to covid and hospitalisation is around two weeks. We're already seeing a drift up in hospitalisations (currently only in working age adults. We're still talking about a relatively small number of omicron cases - we're at least a week from knowing what the hospitalisation profile looks like: by age, by past infection, by double vaxxed, by boosted etc. The raw numbers/rates needed to model what happens next simply don't exist.
Some people are going with caution - assume severity pattern same as delta but with a larger group capable of getting infected and infecting others. In which case we need to slam the infection control brakes on. If it's milder then early controls leave the door open to keeping things normal for family/friends meeting over Christmas without crashing the hospital system by New Year's.
Once you "wait and see" you have zero control over timing of any surge. You either get away with it - and we're all happy or we don't and we've baked in a huge rise in hospitalisations and deaths starting around Christmas and accelerating in January.
For me personally that means no proper parties until Christmas and LFTs in the morning before I meet older/more vulnerable relatives and friends. That pattern won't be true for everyone of course.