That's normal in the UK, singles are usually released later there than other countries. They premiere on radio early on, get radio support, and then when they are released they have a better chance of charting high on the singles chart.
Pre-order most likely. That's very common there. When it's officially released there (July 6th), she'll probably secure the #1 that week.
Is that date confirmed
Ariana tweeted this earlier
Quote:
Ariana Grande @ArianaGrande 10h
UK loves I haven't forgotten about u at all! I'm not sure why songs sometimes get released a few days later there but it's coming. love u