yes, but why did author not use "Universal Quantifier" ∀ in second part of the question like first part?

my doubt is “If a user is active, at least one network link will be available.” if there is no active user, then it should give truth value as "false" but P→Q always gives true if the premise is false. or why can't we use ∀uA(u) → ∃nS(n, available)?

if there is no "active user" won't still it be true?