The ALUT non-unknowability conjecture

Let $\textbf{ALUT}$ be the fragment of formulas under consideration, and let $\textbf{I}$ be the set of agents. For each formula $\varphi\in\textbf{ALUT}$ and each agent $i\in\textbf{I}$, write $U_i\varphi$ for the claim that $\varphi$ is unknowable by agent $i$.

ALUT non-unknowability conjecture. For all $\varphi\in\textbf{ALUT}$ and all $i\in\textbf{I}$,

$$\Vdash \neg U_i\varphi.$$

The conjecture asks whether the entire ALUT fragment contains no unknowable formulas. The supplied text does not establish this claim or indicate whether it is known, so its resolution remains open.