Re: Christmas Time is here!
"With no real world evidence that things will be worse"
Sure, there's no evidence things will be worse, it's hard to have evidence about the future particular when the planned shape of that future has yet to be detemined, but there is evidence that things are already worse.
Most price rises we're seeing now are as a result of a fairly steep decline in the value of GBP against both USD and EUR, causing import costs to sky rocket immediately for any business without currency hedging and with a clear expectation of them sky rocketing for those who did hedge.
With further declines in GBP value likely and expected up until the UK reaches a new deal with the EU and/or Article 50 is actually triggered and the two year leave period has passed, businesses have no choice but to raise prices for the time being. (I admit there may well be some profiteering going on but there are genuine cost increases as well).
Whether GBP will continue to decline after the actual exit/new trade deal negotiation remains to be seen. It's perfectly possible it's value could rise back to where it used to be it. But businesses cannot base their current pricing on the possible value of the currency in an uncertain future in 5 - 10 years time, they can only base it on the current value of the currency and what that makes their costs come out at now and perhaps at best the predicted value of the next year or so.
As for companies saying their prices will continue to rise after Brexit is complete? That seems a perfectly reasonable thing to say, given that the current currency value has dropped and is continuing that trend as a result of the referendum result, but before Brexit has actually happened, it is reasonable to predict that the same trend could continue following the actual exit.
Sure it might not, but would you prefer companies who believe that their prices will be affected to lie to you and tell you that they won't need to put their prices up and if it then turns out they do just say "Sorry we have to charge you more after all"?