Not too late for some wines; might be too late for maybe a big red.
The WE Chocolate Raspberry port is a great wine. If you can get the kit as soon as it is released in (Sept ???), it won' t be its best by Christmas but it will still be good.
Any of the mist wines from WE (sweet summer wines) certainly will be good by Christmas if you start them by September.
For dry red wines, The lower end kits will have a better chance to taste OK by then, but the bigger, premium kits will need more like a year (or more) to be ready.
All this is just my own opinion, though and others may differ.