Comment on "Improved measurement of $\eta \mathrm{/}{\eta }^{\mathrm{\prime }}$ mixing in $B_{(s)}^0\to J\mathrm{/}\psi {\eta }^{(\mathrm{\prime })}$ decays"

Instead of the glueball-${\eta }^{\mathrm{\prime }}$ mixing ansatz, the latest measured ratios of the branching fractions of $B_{(s)}^0\to J\mathrm{/}\psi {\eta }^{(\mathrm{\prime })}$ decays by LHCb can be understood by including the contribution from the light quark annihilation effect enhanced by the QCD ${\mathrm{U}}_A(1)$ anomaly for light pseudoscalar mesons.