This was primarily to reduce exposure to US assets, not to specifically gain exposure to UK assets. In fact, if you look at their holdings you’ll see the relative percent increase is much lower for Sterling than Euro, which could signal lower confidence in GBP than EUR.

True but if they were confident the Sterling was in bigger trouble than the dollar they wouldn't have invested in it.

No, they could believe that UK assets have a different risk profile than US assets and want to diversify, even if they think UK assets have a lower risk-adjusted return. Diversification is valuable.