Plugin Hybrids are a bit different, but are still not electric, and shouldn't enjoy the tax benefits of being electric, and shouldn't be included in stats for electric, because they are not.
I agree they shouldn’t be lumped in with EVs for statistical purposes, but they also shouldn’t be treated the same as ICEs or hybrids. There should still be some measure of the incentives (and penalties) associated with EVs.
We got a tax break when we bought our PHEV, but a lower one than a full EV would get. We also pay more each year for our vehicle registration for road maintenance (since we pay less in gas tax), but less than a full EV would. This all seems fair to me since we can get anywhere from 25-40 miles of pure EV usage on a full charge (depending on how hard we’re driving and how cold it is outside). We’re averaging around 120mpg over the life of the vehicle, far better than a non-plug-in hybrid could hope to achieve.