What is it the characterizes an artist's style? Is it the colours that he uses? Subject matter? The way the paint is applied and brushwork? No doubt all of these features are part of it, but is it important? Is there not more to this topic that requires more insight?
For many who do not paint there is much emphasis placed on an artist's style. In many cases an artist gets pegged to a certain style and finds himself stuck. Use the same "style" to get sales. Change the style and sales fall away. It is a dangerous situation for an artist to stick to one method, because that disempowers the artist. Is it still art to churn out facsimiles of previous work? It brings short term rewards, but long term? Certain stagnation.
I would suggest that instead of a certain style (whatever that means) a true artist will seek only one thing: an interpretation. The artist's identity comes into play when the artist interprets the subject and paints that interpretation. That is the only truth that an artist has. Anything else is a copy of something else.
Looking at Cezanne's painting above it is clear what the subject is. Yet Cezanne's passion for painting this mountain is based not on his love of scenery. It is based on his interpretation of the shapes, light and colour. That is what is unique.
As Cezanne progressed in his interpretation of shapes into increasingly flat planes light itself became less important. He started to use pure colour to suggest shapes instead of light to depict three dimensions. As a result the picture began to flatten to two dimensions. Cezanne probably never intended this at the time, but his quest for purity of shape was how he interpreted the subject.
If an artist is too caught up in producing the same set of bluegum trees or transparent green waves then interpretation is abandoned. There is no more art and we are left with a craft where repetition is all important.
What will the critics say when your landscape undergoes a radical change in approach? Ideally you should not care. Your idea and interpretation is unique to you - the artist. The only constant is change so embrace change. Beware of time leading to sameness. Resist!
In the end all an artist has to say is found on the canvas. Whether the viewer can access the artist's message is not the artist's burden. If the artist is true to his soul then the message will be heard when the time is right. In Cezanne's case the message was heard by some who followed with their own interpretations. One of those was a young artist called Pablo Picasso. The process of change continued.