According to the astronomer I talked to, starlink has a negligible impact on professionals. Some disruption at the beginning, but fairly easy to account for. There is already plenty of man made objects that need to be accounted for like the ISS, any of which could cause an issue but it’s a tiny fraction of data that’s impacted and therefore it can be removed fairly easily.

That said, amateur astronomers doing long exposure shots will likely be impacted.

Simply not true, starlink will have a real impact on research (see e.g. https://www.lsst.org/content/lsst-statement-regarding-increa... for the impact on LSST) and will make some science impossible to do. Ironically, amateur long exposure shots will be fine because amateur astronomy doesn’t rely on pixel-level brightnesses and you can easily subtract out streaks in a way that’s pleasing to the eye. Whether or not you think it’s justified, it’s not true to say this will not impact astronomy. Some science cases will be fine, others will be significantly impacted and still others will be SOL and impossible to do.

So the “Rubin Observatory is an extreme case for the sensitivity of astronomical observations to satellite constellations because of its unprecedented ability to repeatedly monitor the sky widely and deeply.”

And their worried about potentially losing as little as 0.3% of pixel level data, that sounds about right. I am not saying it’s impact is meaningless, just they could offset their impact with funding, rather than it being a massive issue on it’s own.