That's my understanding, the place they are moving to next month is in the same part as BBC Arabic/Persian (Egton Wing) but AIUI the idea is to move the regional TV news into the national news facilities when that moves to the part currently under construction.
I know lots of people want to move into the main BH newsroom, but despite it being the largest in the world there isn't the space for everyone to be in there who wants to be. Out of TV News (Domestic and World), English Radio news (Domestic and WS) and BBC London I'd expect London to be down the priority list for space. If they want Radio, TV and Online to remain together then I'd be really surprised if they found the space for all of them in the main newsroom.
Having said that there have been a number of problems caused by BBC Persian being split up as it currently is (only TV is in Egton, as their floor isn't big enough for Radio as well), so the London floor of Egton would be a potential home for the Persians in the future to unify the service if it were to become vacant.
If you've seen the twitter videos you'll notice that it doesn't look like the most permanant setup.
I didn't think it looked much different to the BBC Arabic or Persian floors in Egton Wing. I agree these don't look as solid as studios built in the past, but that's progress for you.