The main change is that the 10 days home quarantine on arrival in NL is now mandatory for travellers from the UK, instead of only "strongly urgently recommended" before. You must complete a quarantine declaration form in addition to the passenger health form, and you will now be called to check where you are. You can still have a free test to release on Day 5 by phoning the GGD in advance to book, or booking online on Day 5 itself.