I have to agree with the consensus on this one. On a full flight with an equipment change and separate PNRs there's a decent chance of getting split up in order to accommodate those on a single PNR. Unfortunately when the flight is full it's then going to be hard to rectify the problem until boarding.

I'm generally quite relaxed about changing seats to accommodate others provided I'm not in a prime seat and won't be massively inconvenienced. I'm talking mainly AA domestic F here and I do reject moves to the bulkhead because I want my computer under the seat in front of me.

I had my first double move last month. Started in seat my own seat and was asked to move to allow another couple to sit together. Just got settled into the new seat and was asked to move again and ended up in a third seat. These were all requests from passengers and not crew. The shenanigans caused a bit of confusion at meal time. I certainly don't see the need to have a blanket ban on being helpful!