I would imagine so, I still don't quite understand why Desmond insisted on moving it in the first place.
Cost savings in not having to use ITN's studios and newsroom as part of the news contract. Obviously this would have changed since Viacom became the majority shareholder. (N&S are still a minority shareholder in Channel 5 Broadcasting Limited).
The main reason cited for moving to Desmond's building was that he wanted to create a multi-media news hub housing his journalists from print and TV. He did have plans to create a huge new HQ outside London but it was all bluff and hyperbole - exactly what you would expect from the owner of a newspaper that seems to believe Princess Diana is still alive.
Whether or not the news operation is based at Viacom will come down to the practicalities and - IMHO - that will mean ITN housing the newsteam and studio. It's simply a lot easier for Viacom to allow ITN to run the whole thing from their own purpose-built HQ. There is also the issue of total lack of space at Viacom. (That said, I believe ITN is becoming increasingly tight for space, with a number of international broadcasters now also based in there).
That was a very deliberate decision on behalf of the designer... and it would have been a travesty had they converted it into a boring office block. Having been in the new building, it's truly stunning. The coloured stripe motif runs through the whole building in various forms.
Dare I say it, much nicer than the days of Eggcup House.
I remember MTV having a VJ presented show (IIRC by a pre-EastEnders Richard Blackwood) from that part of the building in the early 00s (back when they still showed music and had decent content), and I seem to remember it looking quite a fair bit like it had in the TV-am days.