It was in the FAQs at the back of the 2020 timetable consultation:
“At the time of writing, we expect a number of our EMR Electrics trains to come into passenger service in their current layout – this includes 3+2 seating and small First Class sections at each end of the train. However, all trains will be significantly refurbished in the following months and when complete, all trains will offer 2+2 seating in standard class and larger First Class sections with 2+1 seating, as well as free WiFi, new seats, real time passenger information, improved air conditioning and power sockets.”
However, although there’s no specific reference to 110 mph mods, they probably wouldn’t get mentioned in that sort of context.