There’s no guarantee the new model will be available on the scheme when its first launched, making it a bit of a guessing game. You could leave ordering till the last minute or see you could try requesting a last minute short 6 month extension on your current lease. The risk of this is, if the current model is removed from the scheme and the new model doesn’t join in that time, you will have to look for something else.
Also to add
And worth a mention
Ordering in June avoids the July VAT hike