Yes and no. Those ad threads are special. They are hooked up to the advertising engine that actually shows ads in the sidebar on the main site that get enough upvotes in the current community thread on meta.
Could we add "canned" answers to other posts? Sure. Will we? Highly unlikely.
For one, the current implementation wouldn't work - that placeholder post is the same every time someone goes to post an answer on the community ad question. If we were to generalize it, we'd need to at the very least provide a way to create, maintain, and select from a list of templated answers.
However, if you find that a question can be answered by a stock canned answer, the odds are that there's an existing question somewhere that addresses the same points and it's better to just close the new one as a duplicate.