Can minimalism be sustainable? By any means: yes! It’s a matter of intention only.
Reduce our belongings to that still comfortable minimum… but while at it, why not purify the keepsake objects to those and those alone that have soul, personality, integrity, uniqueness, the genuine, the lasting, the worthy to pass down, those so great that it is nearly irresistible to share them with others?
All of the above are likely to have something to do with natural as is. Now just refine that trait more. Introduce it into your consciousness, into the conscious and responsible decision making. Become responsible not just on a self account, but assume responsibility for the world, too. The destiny of it, the kind of life you imagine the grandchildren of your great-grandchildren would also be proud to bestow on their offspring. These are the eternal values. That can never go out of style, because they are life supporting.
These are the virtuous values not worth compromising for the sake of any fashion trends. It is a designer challenge, too, not everyone is able or interested in meeting. But you be. You become that designer yourself or seek out the one to distinguish you with the kind of personalized attention you are looking for and deserve.
But you know what? These are the same values not worth compromising to inheritance, to hand-me-downs, to traditions not respectful of nature.
Approaching the subject from another angle, minimalism makes a highly suitable entryway to sustainability in that it doesn’t only prevent wastefulness, but keeps redundancies low, fostering an optimal distribution of materials and energies.
So my answer to the original question is definitely affirmative: minimalism and sustainability can align, they can align harmoniously and to people like ourselves it makes a lot of sense. In fact only this make sense. We would love to see more minimalists at heart share this sensitivity and reflect it back upon themselves, upon the rest of the world in a very material sense, too. The world would be a better place.
Perhaps a bit less shiny, but more textured.