I used to work as an engineer for a car company many years ago (GM). Despite that I'm certainly not presenting myself as any expert or fortune teller on this subject, but it was said back then that the Corvettes is what brought people into the showroom to buy the Chevettes (yes I worked there a long time ago).
And although the concept of showrooms is no longer very strong, I think the concept of having a performance pedigree helps to sell your volume cars, despite the low number sold of your halo car. This is my long-winded way of suggesting that, unless and until Lotus' cars other than the Emira reach incredible sales success on their own merits (and given all the other competition that day may never come), they will still need to keep the Emira around for years to come. It's cars like the Emira that keep the notion alive that Lotus is a performance oriented brand with serious racing history and creds that helps people decide to buy a Lotus SUV (EV or hybrid), vs many other choices. Again, just my two.