Remember though that Riverside will be only one TV studio. There will be two other studio spaces but they're not being run by Riverside TV and are intended for live arts
Indeed it will just be Studio 1 that will be leased to Riverside TV. However, with demand for studio space, I do wonder whether they'll consider leasing Studio 2 out in the future too as it is a similar size to Studio 1. I suppose it depends how successful the art spaces are and if they can continually fill both Studio 2 and 3 with productions and exhibitions to make it viable. Although I think revenue from the lease to Riverside TV is meant to be helping fund the arts part of the complex too.
The Cochrane was indeed used for the relaunch of TFI Friday and The Nightly Show https://www.oldcollegeproductionbase.com/filming-locations
I think ITV spent a fair bit removing and updating the alterations made by TFI Friday but I've not heard of it being used much since. It was ironic that ITV put so much seating back in as it was clear they were struggling to fill the seats for the Nightly Show - they ended up with some very tight shots of the first couple of rows by the end of the run!