Reply from plugins@wordpress.org:
Currently that is permitted. As long as it’s 100% dismissable and doesn’t track usage, it’s allowed.
Welp, that is the state of the plugins, folks.
I’m not happy about this, injecting ads into the dashboard rearranges the widgets. Look at this thing:
So in this case, the obscured link beneath the only button on the screen says, “I don’t want a free license; don’t show this again” is allowed.
I believe this is a compromise of our values.