I haven't read any reports on row 21 yet and there is nothing in the BA forum dashboard that points to this either. The aircraft type is very new and reports so far are limited to First, Club World and World Traveller.

I'd expect normal recline in all WT+ seats, including those in the last row. Row 21 is adjacent to the washrooms which does not appear altogether desirable to me. I'll be taking a trip on the 787-9 next week in WT+ so will report back.