The support page describing that repair program in the UK is
here.
Look at the last line in that article.
I think Apple will not use the term "extended warranty", as it is a specific service program, and does NOT extend the standard warranty. Again, near the bottom of that article:
Some keyboard repairs might be covered, but associated issues that might, or might not be part of the keyboard program could interfere with those keyboard repairs, and might be extra charge, or no charge. An example might be a swelling battery possibly making a few keys hard to press. Battery would have to be replaced, which might be charged as not associated with the keyboard repair, or may be included at no charge. That is going to vary from one repair to the next.