you could put it down as a best case scenario, mortgage lenders price their mortgages based on whether they want to have best buy products to increase lending for a period of time possibly due to an influx of deposits, how their competitors are pricing their mortgages.
if you’re rate is due to finish soon, check out what your lender is currently offering as of now, if not a comparison site will give you a general overview of the state of things at the moment.