The Goalpost Safety website link (on the right of this page) states that metal cup hooks on any part of the goal are not permitted and as such matches will be postponed by match officials where these hooks are evident.
Images can be viewed on the right of net fixings which are deemed compliant following the recent British Standards work, so matches where these fixings are apparent are not affected.
The four golden rules of The FA's Goalpost Safety campaign are -
CHECK IT
SECURE IT
TEST IT
RESPECT IT
Keeping safety onside is a team effort and everyone must play their part.