Sure. Generally, it is a marker for life as we see it being produced by living organisms on Earth and it also should vanish quickly from atmospheres if it is not replenished. However, as you correctly put it, there may always be a non-biological explanation as well for any of these marker. So far I know, DMS has no non-biological explanation so far and is seen as a biological marker still.

Alas, the possibility of it being proven non-biological or even (as happend here) not a real detection makes it even more important to get more data and be very careful about the statements made from it than as otherwise those statements and/or connected papers have to be corrected/retracted.