I once had a long chat with a customer services manager about "control" and service recovery. This manager said
i) control valued putting trains back in the right place over passengers
ii) control are "too busy" doing i) to actually inform CS staff as to what is happening
I do recognise that there are multiple perspectives from this and "putting trains back in the right place" can occasionally benefit passengers, but this CSM spoke with a great deal of frustration that they were often unable to pass any information on to passengers because "control" wouldn't let them know what was happening, and that control would often take utterly ridiculous decisions leaving passengers stranded at unstaffed stations for hours on end, with no hope of alternative transport.
Well "Control" have to think about passengers as a big picture. With all due respect to this CSM, who is looking at the local needs of their area, if there is no semblanace of trains "back in the right place" the disruption will go on even longer because then crews and stock will be utterly displaced and then even more people will be disrupted for a longer period. Making short, sharp, prompt decisions can reduced the overall disruption, as can implementing arranged contingency plans.
As for communications, there's some truth in this but when the number of calls per hour goes from say 10 to 100, and the actions needed triples or quadruples, the number of staff within Control doesn't go up 10x, and calls have to be priortised on operational decisions. Occasionally this means that its hard to be abreast of every station issue at once which means there will be gaps in service. Especially true on Thameslink through the core which is very intense. In this instance you'd be looking at turning trains at St Pancras (High Level) and London Bridge, with maybe a service group able to use bays at Blackfriars (if they can weave within the Sevenoaks services). There will be unavoidable large gaps though because you've cut the capacity of the railway significantly - one of the flaws of through running a high-intensity service.
I'd always encourage station management or similar staff to visit their local Control (and vice versa) to see what its like; unfortunately these visits always seem to happen when there's no disruption and people are broadly twiddling their thumbs!