YES IT IS OFFICIAL.
https://www.amazon.co.uk/75969-Harry-Potter-Astronomy-Compatible/dp/B0813QBV6V/ref=pd_rhf_gw_p_img_1?_encoding=UTF8&psc=1&refRID=YSZHTZPJ7PZ8CF3EENNP
IT'S ON THE OFFICIAL PAGE LISTING ON AMAZON UK.
Oh, the Burrow never went up for pre-order in the UK yet. I ordered the rest of the sets straight away. Maybe they aren't doing Burrow pre-orders here as it's a Lego exclusive here.
Not me. Grawp and the Centaurs are long requested creatures, and I am so excited for a real Fawkes! I guess the idea of Grawp being a character can knock people back from considering him a creature, but he is really.