Yes, I have noticed this as well. I think it is because the Soft Underbelly campaign book focuses on the events, situations, and actions of the Sicilian campaign, and only the first stages/phases on the Italian mainland. I believe it is for this reason the Churchill tank was not included in this campaign book. However, it does say under “About this Book” on page 6 that;
“In addition to the Bolt Action rulebook, the reader may
need access to one or more of the ‘Armies of ’ books which
provide rules for many of the units and equipment used by
the armies in this book, mainly those found in the Armies
of the United States, Armies of Great Britain, Armies of
Germany, and Armies of Italy and the Axis supplements.”
So indirectly, the Churchill tank is included even if none of the New Theatre Selectors for the British have it as a choice.
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