It’s more of losing trust in the US. If they don’t believe they’ll have access to it when needed or if they believe it might be seized for whatever made up reason, makes sense to move it somewhere they’ll have control over it.

Why would the dropping value of the USD be a factor in selling gold? Doesn't holding gold hedge against exactly that?

I think the real reason is that they're afraid of political instability in the US that may result in 1) an inability to retrieve their gold, or 2) the government confiscating it.

I don't quite follow. Countries hold gold to protect their own currency from devaluation, not bc they expected it to become stronger against a dollar.

It's more like if you think Trump is likely to say, actually that's my gold.

They think the Trump administration will confiscate it.