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.
All BA LGW routes for winter and summer apart from MAN and GLA have been removed from sale. BA looking to sell their slots allegedly. Not sure if this is tactics to help BALPA decide or BA just walking away.