When a template like

template <typename T>
void unalignedStore(void* const dst, const T& src) noexcept {
  std::memcpy(dst, &src, sizeof(T));
}

is instantiated with Foo* such that Foo is an aggregate, then this produces a diagnostic of bugprone-sizeof-expression:

error: suspicious usage of 'sizeof(A*)' on pointer-to-aggregate type; did you mean 'sizeof(A)'?

I'd say that it generally makes sense to emit a warning if the sizeof expression is of the form sizeof(T) where T is a template type argument.

In addition, even if it makes sense, the diagnostic is not too helpful, as it doesn't mention the context of instantiation or the actual template type argument. A*/A is just a placeholder, which is generally confusing.