Why forty-eight F-35Bs need not be the final British total

Is the United Kingdom likely to buy only forty-eight F-35Bs?

Forty-eight is the forecast for the next three or four years in this 2021 answer. Later batches could increase the total.

The 2021 estimate is for forty-eight F-35Bs over the next three or four years, before the next Parliament. Aircraft purchases proceed in batches, so that forecast leaves room for subsequent orders. The first three Type 26 frigates had prompted a similar misunderstanding about the eventual size of the class. An initial funded batch does not settle the final fleet total.