I wouldn't be surprised if the recent announcement of the proposed change of vehicle tax effective 1st April 2017
https://www.gov.uk/government/publications/vehicle-excise-duty/vehicle-excise-duty put the brakes on Honda's plans for a new hybrid in the UK (I don't think the old one sold very well). In fact, I expect this tax change is going to substantially reduce people's incentives to buy, and hence manufacturers to make, more efficient vehicles. I also expect that Honda would struggle to get the new hybrid's CO2 emission below the 75g/km needed for the London congestion charge exemption (somewhat of a niche market). I am planning to buy my next vehicle before 1st April 2017.
It appears that a version of the new Jazz has CO2 emissions of 106 g/km which is very close to the existing Hybrid's 104g/km (I'm still surprised that Honda didn't put more effort into getting it below the 100 threshold).
The other possible selling reason for a hybrid configuration is improved performance, with the motor working alongside the engine. The powertrain I would have been working on would be to combine a 3 cylinder turbo engine with an upgraded IMA. The electric motor would, among other things, cover the turbo lag. However, dropping in a 1.5 litre engine would probably achieve most of the benefits at lower purchase cost.