When a population is in Hardy-Weinberg equilibrium, the allele frequencies are not changing.
But look at this:
What about an example where disruptive selection favours homozygotes instead of heterozygotes, so the phenotypic frequencies change but the allele frequencies are the same.
Is the population in HWE?
I wouldn’t say they are not changing. Rather, they are in equilibrium.
If the changes are new, then of course the population cannot be in equilibrium, but if kept for long enough, it will reach some equilibrium.