I see this post is almost 2 weeks old, but just wanted to comment. I would be prepared that your outbound flight where you have selected 4A/B, might end up being an A350 with Club Suite. You mention that it is the day flight, assume the BA107? If so then this is currently an A350 for most of this winter season, and that seat map you can see is often used as a placeholder these days for possible A350 routes, plus the number of 777s with that config are fast declining.

Anyway, it may stay as it is, but if I were you I'd check again around the middle of this year to see if it changes. Although it would probably still map you to another window seat, bear in mind that on the Club Suite these are not pairs, so your companion will be on the other side of the aisle and not facing towards you.