Yes, you would now have to wait for a further itinerary change otherwise you will need redemption availability, it's just the involuntary changes that allow a free rebook. But definitely worth bearing in mind. Sofitel is a good quality hotel very handy for Terminal 5, but you may find the walk to the hotel a bit irksome, though no worse than the TWA hotel. The other easy to reach hotel is the Thistle, which is on the car park pod system and is much cheaper, in every sense. There may be slightly less walking there, actually. I have stayed in both, and I think they both have advantages, but the Sofitel would allow a very civilised start to your long haul sector, unfortunately they know this, and charge accordingly.