I can't comment on all, but right now it looks like Italian routes operated out of LGW have been pulled for S22 - nothing to CAG, CTA, BRI in May/June as far as I can see, either through BA.com or Matrix/Google flights. Destinations have disappeared from sale completely rather than being sold from LHR.
Looks like all short-haul from Gatwick. Tenerife and Spanish routes missing too.