In my experience, aluminum left in the dishwasher leaves a residue that can be hard to get off completely. I'm not an expert on the subject, but aluminum is a neurotoxin and is harmful in large amounts, so I would be hesitant to continue to use it whether or not it's still functional.
“Migration of aluminum from food contact materials to food—a health risk for consumers? Part II of III: migration of aluminum from drinking bottles and moka pots made of aluminum to beverages” ⌘ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5388725/
Findings are that drinking coffee from a moka pot made by aluminum will result in a TWI (tolerable weekly intake) of 4%, and that washing the pot in the dishwasher sigificantly increases the aluminum concentration in subsequence brews.
Not sure why people don't use stainless steel versions of them, more durable, nicer, can be used on induction plates. Bialetti has excellent products for this (their pans, not so much).
Practically unkillable if taken a bit of care. At home I use it exclusively for making coffee.
