Considering that insufficient dopamine is one of the main mechanisms behind ADHD - no, you do not want to literally fast from dopamine.
Dopamine fasting is a mechanistic model trying to explain unhealthy behaviour patterns that can occur dozens of times a day.
Even with the little we know about the inner workings of our brains, this doesn't appear to be true: We have to actively build up alternative behaviour and critically inspect/change the cognitions that actually promote the problematic behaviour.
So if a person has unhealthy bevaviour patterns regarding social media consumption, just doing less of that without also actively changing the cognitions that lead to the unhealthy behaviour in the first place won't help much. We do these things because we have a mostly subconsious theory that doing this is good for us. If this actually isn't, than that assumption has to be challenged, and healthy alternatives have to be built up. Just not doing the thing for a while won't replace the assumption, unless one is abstinent for a really long time (think years).
It's not about replacing the assumption. I don't even think there's much of an assumption (that it's good for us), it's rather the opposite: people actually hate themselves for spending so much time on social media, youtube, etc.
So, it's more about kicking a bad habit, than about trying to change some non-existing assumption that it's a good thing.
Besides that potentially fallacious point I made, I don't think the ADHD brain is really relevant to whether dopamine fasting is beneficial for other brains than those with ADHD.