I wouldn't say Apple are a great example, some of their changes aren't always for the best (I own and iPhone and mac). Sometimes they seem to make changes and tell people what they should be doing, instead of listening to what people want. In some ways it means they can progress and implement what they feel is a better design, but then it can also annoy customers. i.e. no headphone sockets, removing ports (hey buy more cables and adapters $$$), no memory card slot, unable to change battery etc etc.
Technology is very different to foods though, when people love the taste of a product they don't like change.
Look back to when Coke changed their recipe, that didn't go down too well, although they did get more sales when they changed back so in the end they managed to save themselves.
Cadburys got a lot of bad press with their changes, especially their creme eggs.
What makes changes more difficult for Huel is that it is a lifestyle changing product, people alter their lives wellbeing and diet around it, so any changes which have a negative outcome for a customer can have a huge impact.
As the market gets bigger for products such as Huel, will they ever consider widening the range rather than just two main products plus gluten free variations to cater for varying tastes? Look how many variations of soft drinks there are now, if the market and demand was there for a v1.2 type product why not consider it rather than just dismiss it?