Removing Flood Shot disables Blizzard Shot

[Paranoia]

Premise: Got Flood Shot. Got Blizzard Shot. Removed Flood Shot.
Result: Blizzard Shot disabled.

Issue: Nothing about Blizzard Shot does not work with base Cast. Nothing thus indicates it would get disabled if I removed Flood Shot or changed to any of the most other Shots that work similar to Flood Shot. Artemis, Zeus and Athena also have similar kinds of Shots.
I could understand if I had upgraded to a Shot that does not work like Flood Shot, like that of Aphrodite or Demeter. But at least base Shot should work since it is 95% the same as Flood Shot.

Tldr: Disabling a Boon because requirement Boon was sold without the base premise for the Boon being affected in any meaningful way seems a tad odd. Not like many other Boons get disabled even if I sell the Boon they required to appear in the first place.