Just read the code on bounce score as I was not sure what happens with it.
The description in Settings says:
The maximum user bounce score before the they are deactivated. A soft bounce adds 1, a hard bounce adds 2.
Based on what I read in the code the following would be clearer.
The maximum user bounce score before we will stop emailing them. A soft bounce adds 1, a hard bounce adds 2. The bounce score get’s reset to zero 30 days after the last bounced email.
At the very least the typo “the they” should be corrected