You can see the influx of presumably hackernews visitors (through GitHub/Google) on the demo instance that's linked from their website :)
https://umami.is/ https://eu.umami.is/share/LGazGOecbDtaIwDr/umami.is
https://umami.is/ https://eu.umami.is/share/LGazGOecbDtaIwDr/umami.is
And if it is, is there that notable an influx?
Zoom out to 90 days, and then today doesn’t seem much different from any other day.