Here’s the FIRST sentence of your link
Effective January 1, 2024, we will introduce a new Unity Runtime Fee that’s based on game installs.
Here’s the details of how the plan will work a few paragraphs down, again from your link
Once a game passes the revenue and install thresholds, the studio would pay a small flat fee for each install (see the table below).
If that wasn’t clear enough, here’s the pricing table. Notice what it refers to? Hint: It’s not downloads
Which is based on downloads.
Source that’s not you pulling it out of your ass? Because your own link disagrees with you
It says so right there. The license is based on installs which will be tracked via downloads:
"We are introducing a Unity Runtime Fee that is based upon each time a qualifying game is downloaded by an end user.