I think Lexus have been reasonably smart here. They've put together a relatively inexpensive face-lift and drawn attention to the model just at a time when people are falling out of love with diesel.
If you only need a compact car, and want better mileage without the use of diesel fuel, options are fairly limited. You have either the Prius, where the looks are too much for some people, Auris or CH-R, Kia Niro or Hyundai Ioniq.
More prestige brands such are relatively expensive plug in hybrids such as the Audi A3 E-Tron and Golf GTE.
I suspect by extending the life of the CT200h, they have probably caught quite a few sales whilst the market is going through this paradigm shift away from diesel while most prestige manufacturers dont have a ready, non-diesel solution.
Might turn out to be a smooth move.
Personally, I'm very happy with my CT200h and even with its idiosyncrasies, I cant find much else to replace it with when my pcp is up. May just buy it outright as GMV might be a shrewd figure with the death of diesel pushing up hybrid second hand values.