Lamborghini's CEO Stefano Domenicali was recently interviewed, and in the interview, there are some shocking hints about future product plans. In particular, he mentioned about the company adding a fourth mainline car to its current lineup of Aventador, Huracán and Urus. Note, this probably wouldn't have any affect on a super-limited production model like the rumored hypercar based on the Terzo Millennio.
The news outlet specifically asked if it would be a successor to the Espada grand touring car, and while doesn't explicitly say that it is, he does mention the importance of space and getting the right powertrain. So it sounds like it will be something at least more practical than the company's current supercars.
Domenicali also noted that we won't be seeing this new fourth Lamborghini for a while. It's targeted to come out between 2025 and 2027. When asked about an electric variant, he said that the current plans are just for a plug-in hybrid version. He doesn't rule out the possibility of a full electric, but the company hasn't seen the demand quite yet for a full electric Lamborghini, and the company would want to work with Volkswagen to figure out how such a car would fit in with the larger corporation's plans and goals. That particular tidbit would be a sign the aforementioned hypercar won't feature an electric powertrain like the Terzo Millennio concept with which it supposedly shares its design.
The other product information Domenicali talked about was related to hybrids. He again confirmed that the next Aventador and Huracán, or whatever the successors are called, will feature plug-in hybrid powertrains.
The first will be a V12 plug-in for the Aventador replacement, and the Huracán replacement will have a V10 plug-in. The company is still working on a Urus plug-in hybrid, too. It has, however, had some problems getting the desired performance from test engines that have included twin-turbo V6s and a V8. You can read more about what's next for Lamborghini in the full Automotive News interview.